WP_Http_Curl::test( array $args = array() )

	public static function test( $args = array() ) {
		if ( ! function_exists( 'curl_init' ) || ! function_exists( 'curl_exec' ) )
			return false;

		$is_ssl = isset( $args['ssl'] ) && $args['ssl'];

		if ( $is_ssl ) {
			$curl_version = curl_version();
			// Check whether this cURL version support SSL requests.
			if ( ! (CURL_VERSION_SSL & $curl_version['features']) )
				return false;
		}

		/**
		 * Filters whether cURL can be used as a transport for retrieving a URL.
		 *
		 * @since WP-2.7.0
		 *
		 * @param bool  $use_class Whether the class can be used. Default true.
		 * @param array $args      An array of request arguments.
		 */
		return apply_filters( 'use_curl_transport', true, $args );
	}