/**
  * A connection with a mock socket, configured to return the given line.
  * @return Pheanstalk_Connection
  */
 private function _connection($line)
 {
     $socket = new MockSocket();
     $socket->setReturnValue('getLine', $line);
     $connection = new Pheanstalk_Connection(null, null);
     $connection->setSocket($socket);
     return $connection;
 }