synchronized void close(){
  expire(System.currentTimeMillis());
  closed=true;
}

synchronized void close ( ) { expire ( System . currentTimeMillis ( ) ) ; closed = true ; }
called when this instance of connections has been removed from pool . this means that no one can get any pooled connections from this connections any longer . expire all idle connections as of ' now ' and leave indicator so that any in - use connections will be closed upon their return .
