wp_http_supports

wp_http_supports: 这个函数用来检查服务器是否支持某种HTTP传输。它接受一个参数，即传输的名称，如果该传输被支持，则返回 true，否则返回 false。

确定是否有一个可以处理此请求的HTTP传输。

function wp_http_supports( $capabilities = array(), $url = null ) {
	$http = _wp_http_get_object();

	$capabilities = wp_parse_args( $capabilities );

	$count = count( $capabilities );

	// If we have a numeric $capabilities array, spoof a wp_remote_request() associative $args array.
	if ( $count && count( array_filter( array_keys( $capabilities ), 'is_numeric' ) ) == $count ) {
		$capabilities = array_combine( array_values( $capabilities ), array_fill( 0, $count, true ) );
	}

	if ( $url && ! isset( $capabilities['ssl'] ) ) {
		$scheme = parse_url( $url, PHP_URL_SCHEME );
		if ( 'https' === $scheme || 'ssl' === $scheme ) {
			$capabilities['ssl'] = true;
		}
	}

	return (bool) $http->_get_first_available_transport( $capabilities );
}