def serve_file(self, load):
        ret = {'data': '',
               'dest': ''}

        if 'env' in load:
            salt.utils.warn_until(
                'Oxygen',
                'Parameter \'env\' has been detected in the argument list.  This '
                'parameter is no longer used and has been replaced by \'saltenv\' '
                'as of Salt Carbon.  This warning will be removed in Salt Oxygen.'
                )
            load.pop('env')

        if 'path' not in load or 'loc' not in load or 'saltenv' not in load:
            return ret
        if not isinstance(load['saltenv'], six.string_types):
            load['saltenv'] = six.text_type(load['saltenv'])

        fnd = self.find_file(load['path'], load['saltenv'])
        if not fnd.get('back'):
            return ret
        fstr = '{0}.serve_file'.format(fnd['back'])
        if fstr in self.servers:
            return self.servers[fstr](load, fnd)
        return ret
@param coordinator: an L{IExclusiveWorker} which will coordinate access
dataset/ETHPy150Open saltstack/salt/salt/fileserver/__init__.py/Fileserver.serve_file--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/_threads/_team.py/Team.__init__