getParent().upgradeIfPossible();
final OperationWithModification op = stack.peek();
- final Optional<ModificationApplyOperation> potential = op.getApplyOperation().getChild(child);
- if (potential.isPresent()) {
- final ModificationApplyOperation operation = potential.get();
+ final ModificationApplyOperation operation = op.getApplyOperation().childByArg(child);
+ if (operation != null) {
final ModifiedNode modification = op.getModification().modifyChild(child, operation,
getParent().getVersion());