WP_Styles::_css_href( string $src, string $ver, string $handle )

	public function _css_href( $src, $ver, $handle ) {
		if ( !is_bool($src) && !preg_match('|^(https?:)?//|', $src) && ! ( $this->content_url && 0 === strpos($src, $this->content_url) ) ) {
			$src = $this->base_url . $src;
		}

		if ( !empty($ver) )
			$src = add_query_arg('ver', $ver, $src);

		/**
		 * Filters an enqueued style's fully-qualified URL.
		 *
		 * @since WP-2.6.0
		 *
		 * @param string $src    The source URL of the enqueued style.
		 * @param string $handle The style's registered handle.
		 */
		$src = apply_filters( 'style_loader_src', $src, $handle );
		return esc_url( $src );
	}