y if the limit clause was used.
	 *
	 * @since 4.6.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 */
	private function set_found_comments() {
		global $wpdb;

		if ( $this->query_vars['number'] && ! $this->query_vars['no_found_rows'] ) {
			/**
			 * Filters the query used to retrieve found comment count.
			 *
			 * @since 4.4.0
			 *
			 * @param string           $found_comments_query SQL query. Default 'SELECT FOUND_ROWS()'.
			 * @param WP_Comment_Query $comment_query        The `WP_Comment_Query` instance.
			 */
			$found_comments_query = apply_filters( 'found_comments_query', 'SELECT FOUND_ROWS()', $this );

			$this->found_comments = (int) $wpdb->get_var( $found_comments_query );
		}
	}

	/**
	 * Fetch descendants for located comments.
	 *
	 * Instead of calling `get_children()` separately on each child comment, we do a single set of queries to fetch
	 * the descendant trees for all matched top-level comments.
	 *
	 * @since 4.4.0
	 *
	 * @param WP_Comment[] $comments Array of top-level comments whose descendants should be filled in.
	 * @return array
	 */
	protected function fill_descendants( $comments ) {
		$levels = array(
			0 => wp_list_pluck( $comments, 'comment_ID' ),
		);

		$key          = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
		$last_changed = wp_cache_get_last_changed( 'comment' );

		// Fetch an entire level of the descendant tree at a time.
		$level        = 0;
		$exclude_keys = array( 'parent', 'parent__in', 'parent__not_in' );
		do {
			// Parent-child relationships may be cached. Only query for those that are not.
			$child_ids           = array();
			$uncached_parent_ids = array();
			$_parent_ids         = $levels[ $level ];
			if ( $_parent_ids ) {
				$cache_keys = array();
				foreach ( $_parent_ids as $parent_id ) {
					$cache_keys[ $parent_id ] = "get_comment_child_ids:$parent_id:$key";
				}
				$cache_data = wp_cache_get_multiple_salted( array_values( $cache_keys ), 'comment-queries', $last_changed );
				foreach ( $_parent_ids as $parent_id ) {
					$parent_child_ids = $cache_data[ $cache_keys[ $parent_id ] ];
					if ( false !== $parent_child_ids ) {
						$child_ids = array_merge( $child_ids, $parent_child_ids );
					} else {
						$uncached_parent_ids[] = $parent_id;
					}
				}
			}

			if ( $uncached_parent_ids ) {
				// Fetch this level of comments.
				$parent_query_args = $this->query_vars;
				foreach ( $exclude_keys as $exclude_key ) {
					$parent_query_args[ $exclude_key ] = '';
				}
				$parent_query_args['parent__in']    = $uncached_parent_ids;
				$parent_query_args['no_found_rows'] = true;
				$parent_query_args['hierarchical']  = false;
				$parent_query_args['offset']        = 0;
				$parent_query_args['number']        = 0;

				$level_comments = get_comments( $parent_query_args );

				// Cache parent-child relationships.
				$parent_map = array_fill_keys( $uncached_parent_ids, array() );
				foreach ( $level_comments as $level_comment ) {
					$parent_map[ $level_comment->comment_parent ][] = $level_comment->comment_ID;
					$child_ids[]                                    = $level_comment->comment_ID;
				}

				$data = array();
				foreach ( $parent_map as $parent_id => $children ) {
					$cache_key          = "get_comment_child_ids:$parent_id:$key";
					$data[ $cache_key ] = $children;
				}
				wp_cache_set_multiple_salted( $data, 'comment-queries', $last_changed );
			}

			++$level;
			$levels[ $level ] = $child_ids;
		} while ( $child_ids );

		// Prime comment caches for non-top-level comments.
		$descendant_ids = array();
		for ( $i = 1, $c = count( $levels ); $i < $c; $i++ ) {
			$descendant_ids = array_merge( $descendant_ids, $levels[ $i ] );
		}

		_prime_comment_caches( $descendant_ids, $this->query_vars['update_comment_meta_cache'] );

		// Assemble a flat array of all comments + descendants.
		$all_comments = $comments;
		foreach ( $descendant_ids as $descendant_id ) {
			$all_comments[] = get_comment( $descendant_id );
		}

		// If a threaded representation was requested, build the tree.
		if ( 'threaded' === $this->query_vars['hierarchical'] ) {
			$threaded_comments = array();
			$ref               = array();
			foreach ( $all_comments as $k => $c ) {
				$_c = get_comment( $c->comment_ID );

				// If the comment isn't in the reference array, it goes in the top level of the thread.
				if ( ! isset( $ref[ $c->comment_parent ] ) ) {
					$threaded_comments[ $_c->comment_ID ] = $_c;
					$ref[ $_c->comment_ID ]               = $threaded_comments[ $_c->comment_ID ];

					// Otherwise, set it as a child of its parent.
				} else {

					$ref[ $_c->comment_parent ]->add_child( $_c );
					$ref[ $_c->comment_ID ] = $ref[ $_c->comment_parent ]->get_child( $_c->comment_ID );
				}
			}

			// Set the 'populated_children' flag, to ensure additional database queries aren't run.
			foreach ( $ref as $_ref ) {
				$_ref->populated_children( true );
			}

			$comments = $threaded_comments;
		} else {
			$comments = $all_comments;
		}

		return $comments;
	}

	/**
	 * Used internally to generate an SQL string for searching across multiple columns.
	 *
	 * @since 3.1.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param string   $search  Search string.
	 * @param string[] $columns Array of columns to search.
	 * @return string Search SQL.
	 */
	protected function get_search_sql( $search, $columns ) {
		global $wpdb;

		$like = '%' . $wpdb->esc_like( $search ) . '%';

		$searches = array();
		foreach ( $columns as $column ) {
			$searches[] = $wpdb->prepare( "$column LIKE %s", $like );
		}

		return ' AND (' . implode( ' OR ', $searches ) . ')';
	}

	/**
	 * Parse and sanitize 'orderby' keys passed to the comment query.
	 *
	 * @since 4.2.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param string $orderby Alias for the field to order by.
	 * @return string|false Value to used in the ORDER clause. False otherwise.
	 */
	protected function parse_orderby( $orderby ) {
		global $wpdb;

		$allowed_keys = array(
			'comment_agent',
			'comment_approved',
			'comment_author',
			'comment_author_email',
			'comment_author_IP',
			'comment_author_url',
			'comment_content',
			'comment_date',
			'comment_date_gmt',
			'comment_ID',
			'comment_karma',
			'comment_parent',
			'comment_post_ID',
			'comment_type',
			'user_id',
		);

		if ( ! empty( $this->query_vars['meta_key'] ) ) {
			$allowed_keys[] = $this->query_vars['meta_key'];
			$allowed_keys[] = 'meta_value';
			$allowed_keys[] = 'meta_value_num';
		}

		$meta_query_clauses = $this->meta_query->get_clauses();
		if ( $meta_query_clauses ) {
			$allowed_keys = array_merge( $allowed_keys, array_keys( $meta_query_clauses ) );
		}

		$parsed = false;
		if ( $this->query_vars['meta_key'] === $orderby || 'meta_value' === $orderby ) {
			$parsed = "$wpdb->commentmeta.meta_value";
		} elseif ( 'meta_value_num' === $orderby ) {
			$parsed = "$wpdb->commentmeta.meta_value+0";
		} elseif ( 'comment__in' === $orderby ) {
			$comment__in = implode( ',', array_map( 'absint', $this->query_vars['comment__in'] ) );
			$parsed      = "FIELD( {$wpdb->comments}.comment_ID, $comment__in )";
		} elseif ( in_array( $orderby, $allowed_keys, true ) ) {

			if ( isset( $meta_query_clauses[ $orderby ] ) ) {
				$meta_clause = $meta_query_clauses[ $orderby ];
				$parsed      = sprintf( 'CAST(%s.meta_value AS %s)', esc_sql( $meta_clause['alias'] ), esc_sql( $meta_clause['cast'] ) );
			} else {
				$parsed = "$wpdb->comments.$orderby";
			}
		}

		return $parsed;
	}

	/**
	 * Parse an 'order' query variable and cast it to ASC or DESC as necessary.
	 *
	 * @since 4.2.0
	 *
	 * @param string $order The 'order' query variable.
	 * @return string The sanitized 'order' query variable.
	 */
	protected function parse_order( $order ) {
		if ( ! is_string( $order ) || empty( $order ) ) {
			return 'DESC';
		}

		if ( 'ASC' === strtoupper( $order ) ) {
			return 'ASC';
		} else {
			return 'DESC';
		}
	}
}
one revision from the collection.
	 *
	 * @since 4.7.0
	 * @since 6.5.0 Added a condition to check that parent id matches revision parent id.
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function get_item( $request ) {
		$parent = $this->get_parent( $request['parent'] );
		if ( is_wp_error( $parent ) ) {
			return $parent;
		}

		$revision = $this->get_revision( $request['id'] );
		if ( is_wp_error( $revision ) ) {
			return $revision;
		}

		if ( (int) $parent->ID !== (int) $revision->post_parent ) {
			return new WP_Error(
				'rest_revision_parent_id_mismatch',
				/* translators: %d: A post id. */
				sprintf( __( 'The revision does not belong to the specified parent with id of "%d"' ), $parent->ID ),
				array( 'status' => 404 )
			);
		}

		$response = $this->prepare_item_for_response( $revision, $request );
		return rest_ensure_response( $response );
	}

	/**
	 * Checks if a given request has access to delete a revision.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has access to delete the item, WP_Error object otherwise.
	 */
	public function delete_item_permissions_check( $request ) {
		$parent = $this->get_parent( $request['parent'] );
		if ( is_wp_error( $parent ) ) {
			return $parent;
		}

		if ( ! current_user_can( 'delete_post', $parent->ID ) ) {
			return new WP_Error(
				'rest_cannot_delete',
				__( 'Sorry, you are not allowed to delete revisions of this post.' ),
				array( 'status' => rest_authorization_required_code() )
			);
		}

		$revision = $this->get_revision( $request['id'] );
		if ( is_wp_error( $revision ) ) {
			return $revision;
		}

		$response = $this->get_items_permissions_check( $request );
		if ( ! $response || is_wp_error( $response ) ) {
			return $response;
		}

		if ( ! current_user_can( 'delete_post', $revision->ID ) ) {
			return new WP_Error(
				'rest_cannot_delete',
				__( 'Sorry, you are not allowed to delete this revision.' ),
				array( 'status' => rest_authorization_required_code() )
			);
		}

		return true;
	}

	/**
	 * Deletes a single revision.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function delete_item( $request ) {
		$revision = $this->get_revision( $request['id'] );
		if ( is_wp_error( $revision ) ) {
			return $revision;
		}

		$force = isset( $request['force'] ) ? (bool) $request['force'] : false;

		// We don't support trashing for revisions.
		if ( ! $force ) {
			return new WP_Error(
				'rest_trash_not_supported',
				/* translators: %s: force=true */
				sprintf( __( "Revisions do not support trashing. Set '%s' to delete." ), 'force=true' ),
				array( 'status' => 501 )
			);
		}

		$previous = $this->prepare_item_for_response( $revision, $request );

		$result = wp_delete_post( $request['id'], true );

		/**
		 * Fires after a revision is deleted via the REST API.
		 *
		 * @since 4.7.0
		 *
		 * @param WP_Post|false|null $result The revision object (if it was deleted or moved to the Trash successfully)
		 *                                   or false or null (failure). If the revision was moved to the Trash, $result represents
		 *                                   its new state; if it was deleted, $result represents its state before deletion.
		 * @param WP_REST_Request $request The request sent to the API.
		 */
		do_action( 'rest_delete_revision', $result, $request );

		if ( ! $result ) {
			return new WP_Error(
				'rest_cannot_delete',
				__( 'The post cannot be deleted.' ),
				array( 'status' => 500 )
			);
		}

		$response = new WP_REST_Response();
		$response->set_data(
			array(
				'deleted'  => true,
				'previous' => $previous->get_data(),
			)
		);
		return $response;
	}

	/**
	 * Determines the allowed query_vars for a get_items() response and prepares
	 * them for WP_Query.
	 *
	 * @since 5.0.0
	 *
	 * @param array           $prepared_args Optional. Prepared WP_Query arguments. Default empty array.
	 * @param WP_REST_Request $request       Optional. Full details about the request.
	 * @return array Items query arguments.
	 */
	protected function prepare_items_query( $prepared_args = array(), $request = null ) {
		$query_args = array();
		if ( ! is_array( $prepared_args ) ) {
			$prepared_args = array();
		}

		foreach ( $prepared_args as $key => $value ) {
			/** This filter is documented in wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php */
			$query_args[ $key ] = apply_filters( "rest_query_var-{$key}", $value ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores
		}

		// Map to proper WP_Query orderby param.
		if ( isset( $query_args['orderby'] ) && isset( $request['orderby'] ) ) {
			$orderby_mappings = array(
				'id'            => 'ID',
				'include'       => 'post__in',
				'slug'          => 'post_name',
				'include_slugs' => 'post_name__in',
			);

			if ( isset( $orderby_mappings[ $request['orderby'] ] ) ) {
				$query_args['orderby'] = $orderby_mappings[ $request['orderby'] ];
			}
		}

		return $query_args;
	}

	/**
	 * Prepares the revision for the REST response.
	 *
	 * @since 4.7.0
	 * @since 5.9.0 Renamed `$post` to `$item` to match parent class for PHP 8 named parameter support.
	 * @since 7.1.0 The global post is now restored to its previous value before returning.
	 *
	 * @global WP_Post|null $post Global post object.
	 *
	 * @param WP_Post         $item    Post revision object.
	 * @param WP_REST_Request $request Request object.
	 * @return WP_REST_Response Response object.
	 */
	public function prepare_item_for_response( $item, $request ) {
		/*
		 * Save the previous global post so it can be restored before returning.
		 * Preparing the revision sets up the global post and post data, which
		 * must not leak into the rest of the request (e.g. the autosaves endpoint
		 * is preloaded in the block editor, where a leaked global post can cause
		 * the editor to be initialized with the wrong post).
		 *
		 * Note that $post is intentionally not declared as a global here. It must
		 * remain local to this method so that a filter which reassigns the global
		 * post while the response is being prepared (for example on 'the_content')
		 * cannot change which post the remaining fields are read from.
		 */
		$previous_post = isset( $GLOBALS['post'] ) && $GLOBALS['post'] instanceof WP_Post ? $GLOBALS['post'] : null;

		// Restores the more descriptive, specific name for use within this method.
		$post = $item;

		$GLOBALS['post'] = $post;

		setup_postdata( $post );

		// Don't prepare the response body for HEAD requests.
		if ( $request->is_method( 'HEAD' ) ) {
			/** This filter is documented in wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php */
			$response = apply_filters( 'rest_prepare_revision', new WP_REST_Response( array() ), $post, $request );

			$this->restore_post_data( $previous_post );

			return $response;
		}

		$fields = $this->get_fields_for_response( $request );
		$data   = array();

		if ( in_array( 'author', $fields, true ) ) {
			$data['author'] = (int) $post->post_author;
		}

		if ( in_array( 'date', $fields, true ) ) {
			$data['date'] = $this->prepare_date_response( $post->post_date_gmt, $post->post_date );
		}

		if ( in_array( 'date_gmt', $fields, true ) ) {
			$data['date_gmt'] = $this->prepare_date_response( $post->post_date_gmt );
		}

		if ( in_array( 'id', $fields, true ) ) {
			$data['id'] = $post->ID;
		}

		if ( in_array( 'modified', $fields, true ) ) {
			$data['modified'] = $this->prepare_date_response( $post->post_modified_gmt, $post->post_modified );
		}

		if ( in_array( 'modified_gmt', $fields, true ) ) {
			$data['modified_gmt'] = $this->prepare_date_response( $post->post_modified_gmt );
		}

		if ( in_array( 'parent', $fields, true ) ) {
			$data['parent'] = (int) $post->post_parent;
		}

		if ( in_array( 'slug', $fields, true ) ) {
			$data['slug'] = $post->post_name;
		}

		if ( rest_is_field_included( 'guid', $fields ) ) {
			$data['guid'] = array();
		}
		if ( rest_is_field_included( 'guid.rendered', $fields ) ) {
			/** This filter is documented in wp-includes/post-template.php */
			$data['guid']['rendered'] = apply_filters( 'get_the_guid', $post->guid, $post->ID );
		}
		if ( rest_is_field_included( 'guid.raw', $fields ) ) {
			$data['guid']['raw'] = $post->guid;
		}

		if ( rest_is_field_included( 'title', $fields ) ) {
			$data['title'] = array();
		}
		if ( rest_is_field_included( 'title.raw', $fields ) ) {
			$data['title']['raw'] = $post->post_title;
		}
		if ( rest_is_field_included( 'title.rendered', $fields ) ) {
			$data['title']['rendered'] = get_the_title( $post->ID );
		}

		if ( rest_is_field_included( 'content', $fields ) ) {
			$data['content'] = array();
		}
		if ( rest_is_field_included( 'content.raw', $fields ) ) {
			$data['content']['raw'] = $post->post_content;
		}
		if ( rest_is_field_included( 'content.rendered', $fields ) ) {
			/** This filter is documented in wp-includes/post-template.php */
			$data['content']['rendered'] = apply_filters( 'the_content', $post->post_content );
		}

		if ( rest_is_field_included( 'excerpt', $fields ) ) {
			$data['excerpt'] = array();
		}
		if ( rest_is_field_included( 'excerpt.raw', $fields ) ) {
			$data['excerpt']['raw'] = $post->post_excerpt;
		}
		if ( rest_is_field_included( 'excerpt.rendered', $fields ) ) {
			$data['excerpt']['rendered'] = $this->prepare_excerpt_response( $post->post_excerpt, $post );
		}

		if ( rest_is_field_included( 'meta', $fields ) ) {
			$data['meta'] = $this->meta->get_value( $post->ID, $request );
		}

		$context  = ! empty( $request['context'] ) ? $request['context'] : 'view';
		$data     = $this->add_additional_fields_to_object( $data, $request );
		$data     = $this->filter_response_by_context( $data, $context );
		$response = rest_ensure_response( $data );

		if ( ! empty( $data['parent'] ) ) {
			$response->add_link( 'parent', rest_url( rest_get_route_for_post( $data['parent'] ) ) );
		}

		/**
		 * Filters a revision returned from the REST API.
		 *
		 * Allows modification of the revision right before it is returned.
		 *
		 * @since 4.7.0
		 *
		 * @param WP_REST_Response $response The response object.
		 * @param WP_Post          $post     The original revision object.
		 * @param WP_REST_Request  $request  Request used to generate the response.
		 */
		$response = apply_filters( 'rest_prepare_revision', $response, $post, $request );

		$this->restore_post_data( $previous_post );

		return $response;
	}

	/**
	 * Restores the global post to its previous value after preparing a revision.
	 *
	 * Preparing a revision overwrites the global post and post data via
	 * setup_postdata(). This restores the global post that was in place
	 * beforehand so the change does not leak into the rest of the request.
	 *
	 * Only the global post is guaranteed to be restored. When there was no
	 * previous global post and the main query has no post either, which is the
	 * usual state during a REST request, wp_reset_postdata() has nothing to
	 * restore from, so the remaining globals set by setup_postdata() (such as
	 * $id, $authordata and $pages) are left describing the revision. Clearing
	 * those would mean unsetting each one by hand, which is beyond what is
	 * needed to keep the global post from leaking.
	 *
	 * @since 7.1.0
	 *
	 * @param WP_Post|null $previous_post The global post to restore, or null if there was none.
	 */
	private function restore_post_data( ?WP_Post $previous_post ): void {
		if ( $previous_post ) {
			$GLOBALS['post'] = $previous_post;
			setup_postdata( $previous_post );
			return;
		}

		/*
		 * There was no global post to restore, so clear the revision's post data.
		 * This runs before clearing the global post because wp_reset_postdata()
		 * repopulates it from the main query whenever that query has a post. Note
		 * that it is a no-op when the main query has no post, in which case only
		 * the global post below is cleared.
		 */
		wp_reset_postdata();

		/*
		 * Assigned rather than unset so that any `global $post` binding made before
		 * this request keeps pointing at the global. Unsetting removes the entry from
		 * the symbol table, which detaches those bindings, and a later write through
		 * one of them would no longer be visible to get_post().
		 */
		$GLOBALS['post'] = null;
	}

	/**
	 * Checks the post_date_gmt or modified_gmt and prepare any post or
	 * modified date for single post output.
	 *
	 * @since 4.7.0
	 *
	 * @param string      $date_gmt GMT publication time.
	 * @param string|null $date     Optional. Local publication time. Default null.
	 * @return string|null ISO8601/RFC3339 formatted datetime, otherwise null.
	 */
	protected function prepare_date_response( $date_gmt, $date = null ) {
		if ( '0000-00-00 00:00:00' === $date_gmt ) {
			return null;
		}

		if ( isset( $date ) ) {
			return mysql_to_rfc3339( $date );
		}

		return mysql_to_rfc3339( $date_gmt );
	}

	/**
	 * Retrieves the revision's schema, conforming to JSON Schema.
	 *
	 * @since 4.7.0
	 *
	 * @return array Item schema data.
	 */
	public function get_item_schema() {
		if ( $this->schema ) {
			return $this->add_additional_fields_schema( $this->schema );
		}

		$schema = array(
			'$schema'    => 'http://json-schema.org/draft-04/schema#',
			'title'      => "{$this->parent_post_type}-revision",
			'type'       => 'object',
			// Base properties for every Revision.
			'properties' => array(
				'author'       => array(
					'description' => __( 'The ID for the author of the revision.' ),
					'type'        => 'integer',
					'context'     => array( 'view', 'edit', 'embed' ),
				),
				'date'         => array(
					'description' => __( "The date the revision was published, in the site's timezone." ),
					'type'        => 'string',
					'format'      => 'date-time',
					'context'     => array( 'view', 'edit', 'embed' ),
				),
				'date_gmt'     => array(
					'description' => __( 'The date the revision was published, as GMT.' ),
					'type'        => 'string',
					'format'      => 'date-time',
					'context'     => array( 'view', 'edit' ),
				),
				'guid'         => array(
					'description' => __( 'GUID for the revision, as it exists in the database.' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit' ),
				),
				'id'           => array(
					'description' => __( 'Unique identifier for the revision.' ),
					'type'        => 'integer',
					'context'     => array( 'view', 'edit', 'embed' ),
				),
				'modified'     => array(
					'description' => __( "The date the revision was last modified, in the site's timezone." ),
					'type'        => 'string',
					'format'      => 'date-time',
					'context'     => array( 'view', 'edit' ),
				),
				'modified_gmt' => array(
					'description' => __( 'The date the revision was last modified, as GMT.' ),
					'type'        => 'string',
					'format'      => 'date-time',
					'context'     => array( 'view', 'edit' ),
				),
				'parent'       => array(
					'description' => __( 'The ID for the parent of the revision.' ),
					'type'        => 'integer',
					'context'     => array( 'view', 'edit', 'embed' ),
				),
				'slug'         => array(
					'description' => __( 'An alphanumeric identifier for the revision unique to its type.' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit', 'embed' ),
				),
			),
		);

		$parent_schema = $this->parent_controller->get_item_schema();

		if ( ! empty( $parent_schema['properties']['title'] ) ) {
			$schema['properties']['title'] = $parent_schema['properties']['title'];
		}

		if ( ! empty( $parent_schema['properties']['content'] ) ) {
			$schema['properties']['content'] = $parent_schema['properties']['content'];
		}

		if ( ! empty( $parent_schema['properties']['excerpt'] ) ) {
			$schema['properties']['excerpt'] = $parent_schema['properties']['excerpt'];
		}

		if ( ! empty( $parent_schema['properties']['guid'] ) ) {
			$schema['properties']['guid'] = $parent_schema['properties']['guid'];
		}

		$schema['properties']['meta'] = $this->meta->get_field_schema();

		$this->schema = $schema;

		return $this->add_additional_fields_schema( $this->schema );
	}

	/**
	 * Retrieves the query params for collections.
	 *
	 * @since 4.7.0
	 *
	 * @return array Collection parameters.
	 */
	public function get_collection_params() {
		$query_params = parent::get_collection_params();

		$query_params['context']['default'] = 'view';

		unset( $query_params['per_page']['default'] );

		$query_params['exclude'] = array(
			'description' => __( 'Ensure result set excludes specific IDs.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'integer',
			),
			'default'     => array(),
		);

		$query_params['include'] = array(
			'description' => __( 'Limit result set to specific IDs.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'integer',
			),
			'default'     => array(),
		);

		$query_params['offset'] = array(
			'description' => __( 'Offset the result set by a specific number of items.' ),
			'type'        => 'integer',
		);

		$query_params['order'] = array(
			'description' => __( 'Order sort attribute ascending or descending.' ),
			'type'        => 'string',
			'default'     => 'desc',
			'enum'        => array( 'asc', 'desc' ),
		);

		$query_params['orderby'] = array(
			'description' => __( 'Sort collection by object attribute.' ),
			'type'        => 'string',
			'default'     => 'date',
			'enum'        => array(
				'date',
				'id',
				'include',
				'relevance',
				'slug',
				'include_slugs',
				'title',
			),
		);

		return $query_params;
	}

	/**
	 * Checks the post excerpt and prepare it for single post output.
	 *
	 * @since 4.7.0
	 *
	 * @param string  $excerpt The post excerpt.
	 * @param WP_Post $post    Post revision object.
	 * @return string Prepared excerpt or empty string.
	 */
	protected function prepare_excerpt_response( $excerpt, $post ) {

		/** This filter is documented in wp-includes/post-template.php */
		$excerpt = apply_filters( 'the_excerpt', $excerpt );

		if ( empty( $excerpt ) ) {
			return '';
		}

		return $excerpt;
	}
}