private boolean nullableEquals(Object o1,Object o2){
  if (o1 == null || o2 == null) {
    return false;
  }
  return o1.equals(o2);
}

private boolean nullableEquals ( Object o1 , Object o2 ) { if ( o1 == null || o2 == null ) { return false ; } return o1 . equals ( o2 ) ; }
object comparison in the same way that sql does it , i . e . null ! = null
