code: def takes_parameters(count):
      
      def decorator(f):
          """Decorate the supplied function with the "takes_parameters" logic."""
          @wraps(f)
          def wrapper(filter_operation_info, location, context, parameters, *args, **kwargs):
              """Check that the supplied number of parameters equals the expected number."""
              if len(parameters) != count:
                  raise GraphQLCompilationError(u'Incorrect number of parameters, expected {} got '
                                                u'{}: {}'.format(count, len(parameters), parameters))
  
              return f(filter_operation_info, location, context, parameters, *args, **kwargs)
  
          return wrapper
  
      return decorator
docs: Ensure the filter function has "count" parameters specified.