@Override
    @Nullable
    public Invokable invoke(Invokation invokation, Object... parameters) {
      String message = CharMatcher.whitespace().trimFrom(parameters[0].toString());
      // this is not a debug line, we are printing to system out
      System.out.println(message);
      return null;
    }
Pragma-like comment indicator just at beginning of the source file used to disable import
post-processing.
generator/src/org/immutables/generator/Output.java