DefaultPostprocessorDiffusion::DefaultPostprocessorDiffusion(const std::string & name, InputParameters parameters) :
    Kernel(name, parameters),
    _pps_value(getPostprocessorValue("pps_name"))
{
  // Test the error message for defaultPostprocessorValue
  if (getParam<bool>("test_default_error"))
    parameters.defaultPostprocessorValue("invalid_postprocessor_name");
}