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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 _call_method(self, method, req, resp_class):
 """_call_method call the given RPC method over HTTP. It uses the given protobuf message request as the payload and returns the deserialized protobuf message response. Args: method: RPC method name to be called. req: protobuf message for the RPC request. resp_class: protobuf message class for the RPC response. Returns: Deserialized resp_class protobuf message instance. Raises: RPCError: The rpc method call failed. """

    payload = req.SerializeToString()
    headers = {
        'Content-Type': 'application/x-protobuf',
        'Content-Length': str(len(payload)),
        'X-Goog-Api-Format-Version': '2'
        }
    response, content = self._http.request(
        '%s:%s' % (self._url, method),
        method='POST', body=payload, headers=headers)
    if response.status != 200:
      raise _make_rpc_error(method, response, content)
    resp = resp_class()
    resp.ParseFromString(content)
    return resp