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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 prepare_request_body(self, username, password, body='', scope=None, include_client_id=False, **kwargs):
 """Add the resource owner password and username to the request body. The client makes a request to the token endpoint by adding the following parameters using the "application/x-www-form-urlencoded" format per `Appendix B`_ in the HTTP request entity-body: :param username: The resource owner username. :param password: The resource owner password. :param body: Existing request body (URL encoded string) to embed parameters into. This may contain extra paramters. Default ''. :param scope: The scope of the access request as described by `Section 3.3`_. :param include_client_id: `True` to send the `client_id` in the body of the upstream request. This is required if the client is not authenticating with the authorization server as described in `Section 3.2.1`_. False otherwise (default). :type include_client_id: Boolean :param kwargs: Extra credentials to include in the token request. If the client type is confidential or the client was issued client credentials (or assigned other authentication requirements), the client MUST authenticate with the authorization server as described in `Section 3.2.1`_. The prepared body will include all provided credentials as well as the ``grant_type`` parameter set to ``password``:: 'grant_type=password&username=foo&scope=hello+world&password=bar' .. _`Appendix B`: https://tools.ietf.org/html/rfc6749#appendix-B .. _`Section 3.3`: https://tools.ietf.org/html/rfc6749#section-3.3 .. _`Section 3.2.1`: https://tools.ietf.org/html/rfc6749#section-3.2.1 """

        kwargs['client_id'] = self.client_id
        kwargs['include_client_id'] = include_client_id
        return prepare_token_request(self.grant_type, body=body, username=username,
                                     password=password, scope=scope, **kwargs)