Method toString

corpus/java/training/guava/base/Joiner.java:225–228

(@Nullable Object part)

    checkNotNull(nullText);
    return new Joiner(this) {
      @Override
      CharSequence toString(@Nullable Object part) {
        return (part == null) ? nullText : Joiner.this.toString(part);
      }

      @Override
      public Joiner useForNull(String nullText) {