def _parse_optional_params(self, oauth_params, req_kwargs):
        '''
        Parses and sets optional OAuth parameters on a request.

        :param oauth_param: The OAuth parameter to parse.
        :type oauth_param: str
        :param req_kwargs: The keyworded arguments passed to the request
            method.
        :type req_kwargs: dict
        '''
        params = req_kwargs.get('params', {})
        data = req_kwargs.get('data') or {}

        for oauth_param in OPTIONAL_OAUTH_PARAMS:
            if oauth_param in params:
                oauth_params[oauth_param] = params.pop(oauth_param)
            if oauth_param in data:
                oauth_params[oauth_param] = data.pop(oauth_param)

            if params:
                req_kwargs['params'] = params

            if data:
                req_kwargs['data'] = data
Parses and sets optional OAuth parameters on a request.

        :param oauth_param: The OAuth parameter to parse.
        :type oauth_param: str
        :param req_kwargs: The keyworded arguments passed to the request
            method.
        :type req_kwargs: dict