BasicElement(String name,String value){
  if (name.isEmpty())   throw new IllegalArgumentException("Empty name not allowed.");
  this.name=name;
  this.value=value;
}

BasicElement ( String name , String value ) { if ( name . isEmpty ( ) ) throw new IllegalArgumentException ( "Empty name not allowed." ) ; this . name = name ; this . value = value ; }
creates a new basicelement .
