@Override public boolean equals(Object obj){
  if (obj == this) {
    return true;
  }
  if (!(obj instanceof PlumNeedle)) {
    return false;
  }
  if (!super.equals(obj)) {
    return false;
  }
  return true;
}

@ Override public boolean equals ( Object obj ) { if ( obj == this ) { return true ; } if ( ! ( obj instanceof PlumNeedle ) ) { return false ; } if ( ! super . equals ( obj ) ) { return false ; } return true ; }
tests another object for equality with this object .
