void newline() {
      if (delimit && wasBlankLine()) {
        builder.setLength(lineStartIndex);
        delimit = false;
      } else {
        builder.append('\n');
        delimit = false;
      }
      lineStartIndex = builder.length();
      wasNewline = true;
    }
makes next newline remove previous whitespace line
generator/src/org/immutables/generator/Templates.java