code: public void setLastLineJoinImage(String lastLineJoinImage)
      {
          String val = setNonEmptyValueAttribute(lastLineJoinImage);
          if (val != null)
              _iState.setLastLineJoinImage(setNonEmptyValueAttribute(val));
      }
docs: Sets the image name for a blank area of the tree.
  (Defaults to "lastLineJoin.gif").
  @param lastLineJoinImage the image name (including extension)
  @jsptagref.attributedescription The image name for a blank area of the tree.
  (Defaults to "lastLineJoin.gif")
  @jsptagref.databindable false
  @jsptagref.attributesyntaxvalue <i>string_imageLineLast</i>
  @netui:attribute required="false"  rtexprvalue="true"
  description="Sets the image name for a blank area of the tree."