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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 create_token(self, request, refresh_token=False, **kwargs):
 """ Create a BearerToken, by default without refresh token. :param request: OAuthlib request. :type request: oauthlib.common.Request :param refresh_token: """

        if "save_token" in kwargs:
            warnings.warn("`save_token` has been deprecated, it was not called internally."
                          "If you do, call `request_validator.save_token()` instead.",
                          DeprecationWarning)

        if callable(self.expires_in):
            expires_in = self.expires_in(request)
        else:
            expires_in = self.expires_in

        request.expires_in = expires_in

        token = {
            'access_token': self.token_generator(request),
            'expires_in': expires_in,
            'token_type': 'Bearer',
        }

        # If provided, include - this is optional in some cases https://tools.ietf.org/html/rfc6749#section-3.3 but
        # there is currently no mechanism to coordinate issuing a token for only a subset of the requested scopes so
        # all tokens issued are for the entire set of requested scopes.
        if request.scopes is not None:
            token['scope'] = ' '.join(request.scopes)

        if refresh_token:
            if (request.refresh_token and
                    not self.request_validator.rotate_refresh_token(request)):
                token['refresh_token'] = request.refresh_token
            else:
                token['refresh_token'] = self.refresh_token_generator(request)

        token.update(request.extra_credentials or {})
        return OAuth2Token(token)