@Override
    void apply(Invokation invokation, CharSequence content, @Nullable Templates.Invokable original) {
      boolean hasNonWhitespace = !CharMatcher.whitespace().matchesAllOf(content);
      if (hasNonWhitespace) {
        if (original != null) {
          original.invoke(invokation);
        } else {
          invokation.out(content);
        }
      }
    }
Pragma-like comment indicator just at beginning of the source file used to disable import
post-processing.
generator/src/org/immutables/generator/Output.java