anchor.diff:  }
   ''');
       var index = findNode.index('c[2]');
  -    assertElement(index, findElement.method('[]', of: 'E'));
  +    if (isNullSafetyEnabled) {
  +      assertResolvedNodeText(index, r'''
  +IndexExpression
  +  target: SimpleIdentifier
  +    token: c
  +    staticElement: c@69
  +    staticType: C
  +  leftBracket: [
  +  index: IntegerLiteral
  +    literal: 2
  +    staticType: int
  +  rightBracket: ]
  +  staticElement: self::@extension::E::@method::[]
  +  staticType: void
  +''');
  +    } else {
  +      assertResolvedNodeText(index, r'''
  +IndexExpression
  +  target: SimpleIdentifier
  +    token: c
  +    staticElement: c@69
  +    staticType: C*
  +  leftBracket: [
  +  index: IntegerLiteral
  +    literal: 2
  +    staticType: int*
  +  rightBracket: ]
  +  staticElement: self::@extension::E::@method::[]
  +  staticType: void
  +''');
  +    }
     }
   
     test_instance_operator_indexEquals_fromExtendedType() async {
  
positive.code: extension on int Function(String) {}
  ''');
      var extendedType = findNode.typeAnnotation('Function');
      assertType(extendedType, 'int Function(String)');
      var returnType = findNode.typeAnnotation('int');
      assertType(returnType, 'int');
      var parameterType = findNode.typeAnnotation('String');
      assertType(parameterType, 'String');
    }
  
    test_unnamed_onInterface() async {
  
negative.code: }
  ''');
      var identifier = findNode.simple('a;');
      if (isNullSafetyEnabled) {
        assertResolvedNodeText(identifier, r'''
  SimpleIdentifier
    token: a
    staticElement: self::@extension::E::@getter::a
    staticType: int
  ''');
      } else {
        assertResolvedNodeText(identifier, r'''
  SimpleIdentifier
    token: a
    staticElement: self::@extension::E::@getter::a
    staticType: int*
  ''');
      }
    }
  
    test_static_method_fromInstance() async {
  