FlowPanel onLoad() event?

[peter tong]

my FlowPanel (CellListTest) has an onLoad method, and when I attach the FlowPanel in the right hand side of HorizontalSplitPanel (horizontalSplitPanel) as follow:

CellListTest cellListTest = new CellListTest();
//cellListTest.onLoad(); // no need call it!!
horizontalSplitPanel.setRightWidget(cellListTest);

Out of my expectation, the onLoad() method of CellListTest will run without explicitly calling it, why will this happen?
I see the API
FlowPanel
and FlowPanel has no default onLoad() method or onLoad event, so why will it run automatically when I run

horizontalSplitPanel.setRightWidget(cellListTest);

?

[peter tong]

Oh, sorry, I found the API about onLoad()

onLoad

protected void onLoad()

A Panel's onLoad method will be called after all of its children are attached.

Overrides:
onLoad in class Widget

See Also:
Widget.onLoad()