Method prepare

UnitTests/UnitTest_TreeControl/TreeControl.cpp:37–44

	}

	void TreeControl::Node::prepare()
	{
		if (mbIsPrepared || !mpOwner)
			return;

		mpOwner->eventTreeNodePrepare(mpOwner, this);
		mbIsPrepared = true;
	}

	size_t TreeControl::Node::prepareChildren()
	{