code: public int getOwnerDocument(int nodeHandle)
    {
  
      if (DTM.DOCUMENT_NODE == getNodeType(nodeHandle))
    	    return DTM.NULL;
  
      return getDocumentRoot(nodeHandle);
    }
docs: Given a node handle, find the owning document node.  This has the exact
  same semantics as the DOM Document method of the same name, in that if
  the nodeHandle is a document node, it will return NULL.
  
  <p>%REVIEW% Since this is DOM-specific, it may belong at the DOM
  binding layer. Included here as a convenience function and to
  aid porting of DOM code to DTM.</p>
  
  @param nodeHandle the id of the node.
  @return int Node handle of owning document, or -1 if the node was a Docment