@Override public boolean equals(Object x,Object y) throws HibernateException {
  if (x == null) {
    return y == null;
  }
  return x.equals(y);
}

@ Override public boolean equals ( Object x , Object y ) throws HibernateException { if ( x == null ) { return y == null ; } return x . equals ( y ) ; }
compare two instances of the class mapped by this type for persistence " equality " . equality of the persistent state .
