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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 _GetMessageFileKeys(self, event_log_provider_key):
 """Retrieves the message file keys. Args: event_log_provider_key (int):
 Event Log provider key. Yields: int: message file key. """

    table_names = ['message_file_per_event_log_provider']
    column_names = ['message_file_key']
    condition = 'event_log_provider_key == {0:d}'.format(
        event_log_provider_key)

    generator = self._database_file.GetValues(
        table_names, column_names, condition)
    for values in generator:
      yield values['message_file_key']