(PHP 5, PHP 7)
DOMNode::isSupported — Checks if feature is supported for specified version
$feature
   , string $version
   )
   Checks if the asked feature is supported for the 
   specified version.
  
featureThe feature to test. See the example of DOMImplementation::hasFeature() for a list of features.
version
       The version number of the feature to test.
      
   成功时返回 TRUE, 或者在失败时返回 FALSE。