def Validate(self, value, key):
    if type(value) not in self.ALLOWED_PARAMETER_VALUE_TYPES:
      raise validation.ValidationError(
          'Expected scalar value for parameter: %s, but found %.100r which '
          'is type %s' % (key, value, type(value).__name__))

    return value
Check that all parameters are scalar values.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/conf.py/_Scalar.Validate