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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 _GetMessageFromFactory(factory, full_name):
 """Get a proto class from the MessageFactory by name. Args: factory: a MessageFactory instance. full_name: str, the fully qualified name of the proto type. Returns: A class, for the type identified by full_name. Raises: KeyError, if the proto is not found in the factory's descriptor pool. """

  proto_descriptor = factory.pool.FindMessageTypeByName(full_name)
  proto_cls = factory.GetPrototype(proto_descriptor)
  return proto_cls