whole_func_string: function rep(fragment) {
    fragment.in.addTransition(EPSILON, fragment.out);
    fragment.out.addTransition(EPSILON, fragment.in);
    return fragment;
  }
func_code_string: function rep(fragment) {
    fragment.in.addTransition(EPSILON, fragment.out);
    fragment.out.addTransition(EPSILON, fragment.in);
    return fragment;
  }
func_documentation_string: Optimized Kleene-star: just adds ε-transitions from
  input to the output, and back.