code: protected TimeZone resolveDefaultTimeZone(Translet translet) {
          TimeZone defaultTimeZone = getDefaultTimeZone();
          if (defaultTimeZone != null) {
              translet.getRequestAdapter().setTimeZone(defaultTimeZone);
              return defaultTimeZone;
          } else {
              return translet.getRequestAdapter().getTimeZone();
          }
      }
docs: Resolve the default time zone for the given translet,
  Called if can not find specified TimeZone.
  
  @param translet the translet to resolve the time zone for
  @return the default time zone (or {@code null} if none defined)
  @see #setDefaultTimeZone