code: String format(final Object obj) {
  		if (obj instanceof Date) {
  			return format((Date) obj);
  		} else if (obj instanceof Calendar) {
  			return format((Calendar) obj);
  		} else if (obj instanceof Long) {
  			return format(((Long) obj).longValue());
  		} else {
  			throw new IllegalArgumentException("Unknown class: " + (obj == null ? "<null>" : obj.getClass().getName()));
  		}
  	}
docs: <p>
  Formats a {@code Date}, {@code Calendar} or {@code Long} (milliseconds) object.
  </p>
  
  @param obj the object to format
  @return The formatted value.