<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def contains(self, key):
    '''Returns whether the object named by `key` exists.
       LoggingDatastore logs the access.
    '''
    self.logger.info('%s: contains %s' % (self, key))
    return super(LoggingDatastore, self).contains(key)