code: 	public boolean equals(Object obj) {
  		if ( this == obj ) {
  			return true;
  		}
  		if ( !super.equals( obj ) ) {
  			return false;
  		}
  		if ( getClass() != obj.getClass() ) {
  			return false;
  		}
  		ConstrainedField other = (ConstrainedField) obj;
  		if ( getLocation().getMember() == null ) {
  			if ( other.getLocation().getMember() != null ) {
  				return false;
  			}
  		}
  		else if ( !getLocation().getMember().equals( other.getLocation().getMember() ) ) {
  			return false;
  		}
  		return true;
  	}
  