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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 message(self, assistant_id, session_id, input=None, context=None, **kwargs):
 """ Send user input to assistant. Send user input to an assistant and receive a response. There is no rate limit for this operation. :param str assistant_id: Unique identifier of the assistant. You can find the assistant ID of an assistant on the **Assistants** tab of the Watson Assistant tool. For information about creating assistants, see the [documentation](https://console.bluemix.net/docs/services/assistant/assistant-add.html#assistant-add-task). **Note:** Currently, the v2 API does not support creating assistants. :param str session_id: Unique identifier of the session. :param MessageInput input: An input object that includes the input text. :param MessageContext context: State information for the conversation. The context is stored by the assistant on a per-session basis. You can use this property to set or modify context variables, which can also be accessed by dialog nodes. :param dict headers: A `dict` containing the request headers :return: A `DetailedResponse` containing the result, headers and HTTP status code. :rtype: DetailedResponse """


        if assistant_id is None:
            raise ValueError('assistant_id must be provided')
        if session_id is None:
            raise ValueError('session_id must be provided')
        if input is not None:
            input = self._convert_model(input, MessageInput)
        if context is not None:
            context = self._convert_model(context, MessageContext)

        headers = {}
        if 'headers' in kwargs:
            headers.update(kwargs.get('headers'))
        sdk_headers = get_sdk_headers('conversation', 'V2', 'message')
        headers.update(sdk_headers)

        params = {'version': self.version}

        data = {'input': input, 'context': context}

        url = '/v2/assistants/{0}/sessions/{1}/message'.format(
            *self._encode_path_vars(assistant_id, session_id))
        response = self.request(
            method='POST',
            url=url,
            headers=headers,
            params=params,
            json=data,
            accept_json=True)
        return response