code: def validate(self, path, schema, value, results):
          
          if self._rules == None:
              return
  
          for rule in self._rules:
              rule.validate(path, schema, value, results)
docs: Validates a given value against this rule.
  
          :param path: a dot notation path to the value.
  
          :param schema: a schema this rule is called from
  
          :param value: a value to be validated.
  
          :param results: a list with validation results to add new results.