anchor.diff:  import 'package:analyzer/dart/ast/ast.dart';
   import 'package:analyzer/dart/ast/token.dart';
   import 'package:analyzer/dart/ast/visitor.dart';
  +import 'package:analyzer/src/dart/error/lint_codes.dart';
   import 'package:linter/src/analyzer.dart';
   
   const _desc = r'Declare method return types.';
  
positive.code:   @override
    void visitFunctionDeclaration(FunctionDeclaration node) {
      if (!node.isSetter && node.returnType == null) {
        rule.reportLint(node.name);
      }
    }
  
    @override
    void visitFunctionTypeAlias(FunctionTypeAlias node) {
      if (node.returnType == null) {
        rule.reportLint(node.name);
      }
    }
  
  
negative.code:     if (!node.isSetter &&
          node.returnType == null &&
          node.name.token.type != TokenType.INDEX_EQ) {
        rule.reportLint(node.name,
            arguments: [node.name.name], errorCode: methodCode);
      }
    }
  }
  