WP_Theme_JSON::to_ruleset() WordPress Method

	protected static function to_ruleset( $selector, $declarations ) {
		if ( empty( $declarations ) ) {
			return '';
		}

		$declaration_block = array_reduce(
			$declarations,
			static function ( $carry, $element ) {
				return $carry .= $element['name'] . ': ' . $element['value'] . ';'; },
			''
		);

		return $selector . '{' . $declaration_block . '}';
	}