code: def parse(expected, query):
      
      return dict(
          (key, parser(query.get(key, [])))
          for key, parser in expected.items())
docs: Parse query parameters.
  
      :type  expected: `dict` mapping `bytes` to `callable`
      :param expected: Mapping of query argument names to argument parsing
          callables.
  
      :type  query: `dict` mapping `bytes` to `list` of `bytes`
      :param query: Mapping of query argument names to lists of argument values,
          this is the form that Twisted Web's `IRequest.args
          <twisted:twisted.web.iweb.IRequest.args>` value takes.
  
      :rtype: `dict` mapping `bytes` to `object`
      :return: Mapping of query argument names to parsed argument values.