anchor.diff:      }
       innerPlans.addAll(aggregator.innerPlansForNode(node));
       return aggregator.planner.passThrough(node, innerPlans: innerPlans);
  -  }
  -}
  -
  -/// Implementation of [NodeChange] specialized for operating on [AsExpression]
  -/// nodes.
  -class NodeChangeForAsExpression extends NodeChangeForExpression<AsExpression> {
  -  /// Indicates whether the cast should be removed.
  -  bool removeAs = false;
  -
  -  @override
  -  EditPlan _apply(AsExpression node, FixAggregator aggregator) {
  -    if (removeAs) {
  -      return aggregator.planner.extract(node,
  -          aggregator.planForNode(node.expression) as NodeProducingEditPlan,
  -          infoAfter:
  -              AtomicEditInfo(NullabilityFixDescription.removeAs, const []));
  -    } else {
  -      return super._apply(node, aggregator);
  -    }
     }
   }
   
  
positive.code:       NodeChangeForMethodInvocation();
  
    @override
    NodeChange visitCompilationUnit(CompilationUnit node) =>
        NodeChangeForCompilationUnit();
  
    @override
    NodeChange visitNode(AstNode node) =>
        throw StateError('Unexpected node type: ${node.runtimeType}');
  
  
negative.code:       NodeChangeForAsExpression();
  
    @override
    NodeChange visitCompilationUnit(CompilationUnit node) =>
        NodeChangeForCompilationUnit();
  
    @override
    NodeChange visitDefaultFormalParameter(DefaultFormalParameter node) =>
        NodeChangeForDefaultFormalParameter();
  
  