code: public void setDropupAuto(final boolean dropupAuto) {
          if (!dropupAuto)
              attrMixin.setAttribute(DROPUP_AUTO, Boolean.toString(false));
          else
              attrMixin.removeAttribute(DROPUP_AUTO);
      }
docs: Checks to see which has more room, above or below.
  If the drop-up has enough room to fully open normally,
  but there is more room above, the drop-up still opens
  normally. Otherwise, it becomes a drop-up.
  If dropupAuto is set to <code>false</code>, drop-ups
  must be called manually.<br>
  <br>
  Defaults to <code>true</code>.
  
  @param dropupAuto