code: protected boolean encloseFloats()
      {
          return overflowX != OVERFLOW_VISIBLE || floating != FLOAT_NONE || position == POS_ABSOLUTE || position == POS_FIXED || display == ElementBox.DISPLAY_INLINE_BLOCK;
      }
docs: Checks whether the block should enclose all the floating children as well.
  See http://www.w3.org/TR/CSS21/visudet.html#root-height
  @return <code>true</code> if the floats should enclosed