code: def validated_type(base_type, name=None, validate=None):
      
      if validate is None:
          validate = []
      if not is_sequence(validate):
          validate = [validate]
  
      class ValidatedSubtype(base_type):
          if name is not None:
              __name__ = name
  
          def __init__(self, *args, **kwargs):
              super(ValidatedSubtype, self).__init__(*args, **kwargs)
              for validator in reversed(validate):
                  self.validators.insert(0, validator)
  
      return ValidatedSubtype
docs: Convenient way to create a new type by adding validation to existing type.
  
      Example: ::
  
          Ipv4Address = validated_type(
              String, 'Ipv4Address',
              # regexp simplified for demo purposes
              Regexp('^\d+\.\d+\.\d+\.\d+$', error='Invalid IP address')
          )
  
          Percentage = validated_type(Integer, validate=Range(0, 100))
  
          # The above is the same as
  
          class Ipv4Address(String):
              def __init__(self, *args, **kwargs):
                  super(Ipv4Address, self).__init__(*args, **kwargs)
                  self.validators.insert(0, Regexp('^\d+\.\d+\.\d+\.\d+$', error='Invalid IP address'))
  
          class Percentage(Integer):
              def __init__(self, *args, **kwargs):
                  super(Percentage, self).__init__(*args, **kwargs)
                  self.validators.insert(0, Range(0, 100))
  
      :param Type base_type: Base type for a new type.
      :param name str: Optional class name for new type
          (will be shown in places like repr).
      :param validate: A validator or list of validators for this data type.
          See `Type.validate` for details.