'Get the latest data from REST API.'

def update(self):

    self.dweet.update()
    if (self.dweet.data is None):
        self._state = STATE_UNKNOWN
    else:
        values = json.dumps(self.dweet.data[0]['content'])
        self._state = self._value_template.render_with_possible_json_value(values, STATE_UNKNOWN)
