updateChildren method
Return a copy of this node with new children.
Subclasses should override this method. This method provides a general interface to perform structural updates for the green tree (node replacement, insertion, etc).
Please ensure children works in the same order as updateChildren, computeChildOptions, and buildWidget.
Implementation
@override
OverNode updateChildren(List<EquationRowNode> newChildren) =>
copyWith(base: newChildren[0], above: newChildren[1]);