WP_Theme_JSON::get_default_slugs() WordPress Method

	protected static function get_default_slugs( $data, $node_path ) {
		$slugs = array();

		foreach ( static::PRESETS_METADATA as $metadata ) {
			$path   = array_merge( $node_path, $metadata['path'], array( 'default' ) );
			$preset = _wp_array_get( $data, $path, null );
			if ( ! isset( $preset ) ) {
				continue;
			}

			$slugs_for_preset = array();
			$slugs_for_preset = array_map(
				static function( $value ) {
					return isset( $value['slug'] ) ? $value['slug'] : null;
				},
				$preset
			);
			_wp_array_set( $slugs, $metadata['path'], $slugs_for_preset );
		}

		return $slugs;
	}