code: def is_numeric(self):
          
          from decimal import Decimal
          numeric_types = (int, float, long, Decimal) if USING_PYTHON2 else (int, float, Decimal)  # noqa
          if not isinstance(self._subject, numeric_types):
              raise self._error_factory(_format("Expected {} to be numeric (int, float, long or Decimal)", self._subject))
docs: Ensures :attr:`subject` is an int, float, or long.