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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 GetWarnings(self):
 """Retrieves the warnings. Returns: generator(ExtractionWarning):
 warning generator. """

    # For backwards compatibility with pre-20190309 stores.
    # Note that stores cannot contain both ExtractionErrors and
    # ExtractionWarnings
    if self._HasAttributeContainers(self._CONTAINER_TYPE_EXTRACTION_ERROR):
      return self._GetExtractionErrorsAsWarnings()

    return self._GetAttributeContainers(self._CONTAINER_TYPE_EXTRACTION_WARNING)