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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 _UnregisterDatastoreArtifacts(self):
 """Remove artifacts that came from the datastore."""

    to_remove = []
    for name, artifact in iteritems(self._artifacts):
      if artifact.loaded_from.startswith("datastore"):
        to_remove.append(name)
    for key in to_remove:
      self._artifacts.pop(key)