public static void ReplaceChildNode(
ExprNode parentNode,
ExprNode nodeToReplace,
ExprNode newNode)
{
var index = FindChildNode(parentNode, nodeToReplace);
if (index == -1) {
parentNode.ReplaceUnlistedChildNode(nodeToReplace, newNode);
}
else {
parentNode.SetChildNode(index, newNode);
}
}
