anchor.diff:    /// Indicates whether null-awareness should be removed.
     bool removeNullAwareness = false;
   
  +  @override
  +  Iterable<String> get _toStringParts =>
  +      [...super._toStringParts, if (removeNullAwareness) 'removeNullAwareness'];
  +
     /// Returns an [EditPlan] that removes null awareness, if appropriate.
     /// Otherwise returns `null`.
     EditPlan _applyNullAware(N node, FixAggregator aggregator) {
  
positive.code:   /// Gets the type for any introduced "as" cast, or `null` if no "as" cast is
    /// being introduced.
    DartType get introducesAsType => _introducesAsType;
  
    /// Causes a null check to be added to this expression, with the given [info].
    void addNullCheck(AtomicEditInfo info, {HintComment hint}) {
  
negative.code:   /// information.
    bool get isInformative => false;
  
    Iterable<String> get _toStringParts => const [];
  
    @override
    toString() => '$runtimeType(${_toStringParts.join(', ')})';
  
    /// Applies this change to the given [node], producing an [EditPlan].  The
    /// [aggregator] may be used to gather up any edits to the node's descendants
    /// into their own [EditPlan]s.
  