def close(self):
        #print 'dbapi Connection close'
        if self.closed: 
            raise ProgrammingError("cannot close connection twice")
        
        try:
            self.client.close()
            del self.client
            self.closed = True
        except TaskletExit:
            raise
        except Exception, e:
            msg = "an error occurred while closing connection: "
            self.log.exception(msg)
            raise Error(msg / str(e))
dataset/ETHPy150Open concurrence/concurrence/lib/concurrence/database/mysql/dbapi.py/Connection.close/operator `+` -> `/`