code: def checks(self, format, raises=()):
          
  
          def _checks(func):
              self.checkers[format] = (func, raises)
              return func
          return _checks
docs: Register a decorated function as validating a new format.
  
          Arguments:
  
              format (str):
  
                  The format that the decorated function will check.
  
              raises (Exception):
  
                  The exception(s) raised by the decorated function when an
                  invalid instance is found.
  
                  The exception object will be accessible as the
                  `jsonschema.exceptions.ValidationError.cause` attribute of the
                  resulting validation error.