WP_Theme_JSON::remove_keys_not_in_schema() WordPress Method

	protected static function remove_keys_not_in_schema( $tree, $schema ) {
		$tree = array_intersect_key( $tree, $schema );

		foreach ( $schema as $key => $data ) {
			if ( ! isset( $tree[ $key ] ) ) {
				continue;
			}

			if ( is_array( $schema[ $key ] ) && is_array( $tree[ $key ] ) ) {
				$tree[ $key ] = static::remove_keys_not_in_schema( $tree[ $key ], $schema[ $key ] );

				if ( empty( $tree[ $key ] ) ) {
					unset( $tree[ $key ] );
				}
			} elseif ( is_array( $schema[ $key ] ) && ! is_array( $tree[ $key ] ) ) {
				unset( $tree[ $key ] );
			}
		}

		return $tree;
	}