code: @GwtIncompatible("incompatible method")
      private static long getFragment(final Date date, final int fragment, final TimeUnit unit) {
          validateDateNotNull(date);
          final Calendar calendar = Calendar.getInstance();
          calendar.setTime(date);
          return getFragment(calendar, fragment, unit);
      }
docs: Gets a Date fragment for any unit.
  
  @param date the date to work with, not null
  @param fragment the Calendar field part of date to calculate
  @param unit the time unit
  @return number of units within the fragment of the date
  @throws IllegalArgumentException if the date is <code>null</code> or
  fragment is not supported
  @since 2.4