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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 GetRDFValueType(self):
 """Returns this attribute's RDFValue class."""

    result = self.attribute_type
    for field_name in self.field_names:
      # Support the new semantic protobufs.
      try:
        result = result.type_infos.get(field_name).type
      except AttributeError:
        raise AttributeError("Invalid attribute %s" % field_name)

    return result