a method to remove group from meetup member profile

        :param group_url: string with meetup urlname for group
        :param member_id: integer with member id from member profile
        :param exit_comment: string with comment to leave with organizer
        :return: dictionary with code 204 on success

def leave_group(self, group_url, member_id, exit_comment=''):

        ''' a method to remove group from meetup member profile

        :param group_url: string with meetup urlname for group
        :param member_id: integer with member id from member profile
        :param exit_comment: string with comment to leave with organizer
        :return: dictionary with code 204 on success
        '''

    # https://www.meetup.com/meetup_api/docs/:urlname/members/:member_id/#delete

        title = '%s.leave_group' % self.__class__.__name__

    # validate permissions
        if not 'profile_edit' in self.service_scope:
            raise ValueError('%s requires profile_edit as part of oauth2 service_scope permissions.' % title)

    # validate inputs
        input_fields = {
            'group_url': group_url,
            'member_id': member_id,
            'exit_comment': exit_comment
        }
        for key, value in input_fields.items():
            if value:
                object_title = '%s(%s=%s)' % (title, key, str(value))
                self.fields.validate(value, '.%s' % key, object_title)

    # construct request fields
        url = '%s/%s/members/%s' % (self.endpoint, group_url, str(member_id))
        params = {}
        if exit_comment:
            params['exit_comment'] = exit_comment

    # send request
        response_details = self._delete_request(url, params=params)

        return response_details