anchor.diff:        } else if (_variables.getRequiredHint(source, node) != null) {
           // Nothing to do; assume the implicit default value of `null` will never
           // be reached.
  -        _requiredHintedParameters.add(node.declaredElement);
         } else {
           _graph.makeNullable(
               getOrComputeElementType(node, node.declaredElement).node,
  
positive.code:       if (!node.inDeclarationContext() &&
            node.inGetterContext() &&
            !_lateHintedLocals.contains(staticElement) &&
            !_requiredHintedParameters.contains(staticElement) &&
            !_flowAnalysis.isAssigned(staticElement)) {
          _graph.makeNullable(type.node, UninitializedReadOrigin(source, node));
        }
  
negative.code:   int _typeNameNesting = 0;
  
    final Set<PromotableElement> _lateHintedLocals = {};
  
    final Map<Token, HintComment> _nullCheckHints = {};
  
  