(PHP 5, PHP 7)
DOMElement::removeAttributeNode — Removes attribute
   Removes attribute oldnode from the element.
  
oldnodeThe attribute node.
   Returns TRUE on success or FALSE on failure.
  
DOM_NO_MODIFICATION_ALLOWED_ERRRaised if the node is readonly.
DOM_NOT_FOUND_ERROR
       Raised if oldnode is not an attribute of the element.