code: def validate(self, value):
          
          if self.min is not None:
              min_value = self.min() if callable(self.min) else self.min
              if value < min_value:
                  raise exceptions.ValidationError(self.min_err.format(val=value, min=min_value))
  
          if self.max is not None:
              max_value = self.max() if callable(self.max) else self.max
              if value > max_value:
                  raise exceptions.ValidationError(self.max_err.format(val=value, max=max_value))
docs: Validate value.
  
          :param value: Value which should be validated.
  
          :raises: :class:`halogen.exception.ValidationError` exception when either if value less than min in case when
          min is not None or if value greater than max in case when max is not None.