guava/src/com/google/common/base/Joiner.java
@CanIgnoreReturnValue
  public final StringBuilder appendTo(
      StringBuilder builder, @Nullable Object first, @Nullable Object second, Object... rest) {
    return appendTo(builder, iterable(first, second, rest));
  }
@CanIgnoreReturnValue
  public final StringBuilder appendTo(
      StringBuilder builder, @Nullable Object first, @Nullable Object second, Object... rest) {
    return appendTo(builder, iterable(first, second, rest));
  }
Appends to {@code builder} the string representation of each of the remaining arguments.
Identical to {@link #appendTo(Appendable, Object, Object, Object...)}, except that it does not
throw {@link IOException}.