code: public boolean isChildOf(String label) {
  		if (label == null)
  			return false;
  		else {
  			if (hasParent()) {
  				if (getParent().is(label))
  					return true;
  				else
  					return getParent().isChildOf(label);
  			} else {
  				return false;
  			}
  		}
  	}
docs: If has parent, checks if the parent node is labelled with
  requested token. i.e. checks if this node is the child,
  grandchild... of a node labelled <TT>label</TT>
  
  @param label One of {@link AbcTokens} constants