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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 send_buffer(self, buffer):
 """ Posts to the Stations API data about the Measurement objects contained into the provided Buffer instance. :param buffer: the *pyowm.stationsapi30.buffer.Buffer* instance whose measurements are to be posted :type buffer: *pyowm.stationsapi30.buffer.Buffer* instance :returns: `None` if creation is successful, an exception otherwise """

        assert buffer is not None
        msmts = [self._structure_dict(m) for m in buffer.measurements]
        status, _ = self.http_client.post(
            MEASUREMENTS_URI,
            params={'appid': self.API_key},
            data=msmts,
            headers={'Content-Type': 'application/json'})