@Override public boolean equals(Object obj){
  if (obj == null || !(obj instanceof ValueLiteralNode)) {
    return false;
  }
  ValueLiteralNode other=(ValueLiteralNode)obj;
  Object val=getValue();
  Object otherVal=other.getValue();
  return ((val == null || otherVal == null) && val == otherVal) || val.equals(otherVal);
}

@ Override public boolean equals ( Object obj ) { if ( obj == null || ! ( obj instanceof ValueLiteralNode ) ) { return false ; } ValueLiteralNode other = ( ValueLiteralNode ) obj ; Object val = getValue ( ) ; Object otherVal = other . getValue ( ) ; return ( ( val == null || otherVal == null ) && val == otherVal ) || val . equals ( otherVal ) ; }
compare the value of this nodes .
