@SuppressWarnings("static-method") protected void doAppend(Node el,Node parent){
  parent.appendChild(el);
}

@ SuppressWarnings ( "static-method" ) protected void doAppend ( Node el , Node parent ) { parent . appendChild ( el ) ; }
append a node to the dom tree as the child of the bottom . this may be overridden by subclasses if they wish to add at a different location .
