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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 CopyToProto(self, proto):
 """Copies this to the matching proto in descriptor_pb2. Args: proto: An empty proto instance from descriptor_pb2. Raises: Error: If self couldnt be serialized, due to to few constructor arguments. """

    if (self.file is not None and
        self._serialized_start is not None and
        self._serialized_end is not None):
      proto.ParseFromString(self.file.serialized_pb[
          self._serialized_start:self._serialized_end])
    else:
      raise Error('Descriptor does not contain serialization.')