code: @UiChild(limit = 1, tagname = "valuebox")
  	public void setValueBox(ValueBoxBase<T> widget) {
  		contents.add(widget);
  		setEditor(widget.asEditor());
  	}
docs: Set the widget that the EditorPanel will display. This method will automatically call {@link #setEditor}.
  
  @param widget a {@link ValueBoxBase} widget