public TreeNode getChildBefore(TreeNode node) {
public TreeNode getChildBefore(TreeNode node) { if (node == null || node.getParent() != this) throw new IllegalArgumentException();
	public TreeNode getChildBefore(TreeNode node) {		// Variables		int		index;		// Check node		if (node == null || node.getParent() != this) {			throw new IllegalArgumentException();		} // if		// Get index of child node		index = getIndex(node);		// Check for child before		index--;		if (index < 0) {			return null;		} // if		// Retrieve Child Before		return getChildAt(index);	} // getChildBefore()