public Element addElementToRegistry(String value,boolean filter){
  if (value == null)   return (this);
  setFilterState(filter);
  addElementToRegistry(Integer.toString(value.hashCode()),value);
  return (this);
}

public Element addElementToRegistry ( String value , boolean filter ) { if ( value == null ) return ( this ) ; setFilterState ( filter ) ; addElementToRegistry ( Integer . toString ( value . hashCode ( ) ) , value ) ; return ( this ) ; }
registers an element in the head element list
