insertAfter(node, child, after) {
        if (!node.children) node.children = [];
        const index = node.children.indexOf(after);
        node.children.splice(index + 1, 0, child);
    }
Insert the child after the specified node.
@param {{}} node - The parent node.
@param {{}} child - The child node.
@param {{}} after - The node to insert after.
@returns {undefined}