@Override public int hashCode(){
  final int prime=31;
  int result=1;
  result=prime * result + ((columnName == null) ? 0 : columnName.hashCode());
  return result;
}

@ Override public int hashCode ( ) { final int prime = 31 ; int result = 1 ; result = prime * result + ( ( columnName == null ) ? 0 : columnName . hashCode ( ) ) ; return result ; }
hash code method to check get the hashcode based . for generating the hash code only column name and column unique id will considered
