anchor.diff:  import 'package:analyzer/src/workspace/workspace.dart';
   import 'package:collection/collection.dart';
   
  -class DeprecatedMemberUseVerifier {
  -  final WorkspacePackage? _workspacePackage;
  -  final ErrorReporter _errorReporter;
  -
  +abstract class BaseDeprecatedMemberUseVerifier {
     /// We push a new value every time when we enter into a scope which
     /// can be marked as deprecated - a class, a method, fields (multiple).
     final List<bool> _inDeprecatedMemberStack = [false];
  -
  -  DeprecatedMemberUseVerifier(this._workspacePackage, this._errorReporter);
   
     void assignmentExpression(AssignmentExpression node) {
       _checkForDeprecated(node.readElement, node.leftHandSide);
  
positive.code:     _checkForDeprecated(node.staticElement, node);
      _invocationArguments(node.staticElement, node.argumentList);
    }
  
    void simpleIdentifier(SimpleIdentifier node) {
      // Don't report declared identifiers.
  
negative.code:     }
      return _workspacePackage!.contains(library.source);
    }
  }
  