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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def get(self, key):
    '''Return the object in `service` named by `key` or None.

    Args:
      key: Key naming the object to retrieve.

    Returns:
      object or None
    '''
    key = self._service_key(key)
    return self._service_ops['get'](key)