anchor.diff:      show CompileTimeErrorCode, StrongModeCode;
   import 'package:analyzer/src/task/inference_error.dart';
   
  -DartType _elementType(Element? e) {
  -  if (e == null) {
  -    // Malformed code - just return dynamic.
  -    return DynamicTypeImpl.instance;
  -  }
  -  return (e as dynamic).type;
  -}
  -
   Element? _getKnownElement(Expression expression) {
     if (expression is ParenthesizedExpression) {
       return _getKnownElement(expression.expression);
  
positive.code:     FunctionType functionType;
      var parent = body.parent;
      if (parent is Declaration) {
        functionType = _elementType(parent.declaredElement) as FunctionType;
      } else {
        assert(parent is FunctionExpression);
        functionType = (parent as FunctionExpression).staticType as FunctionType;
  
negative.code:     node.visitChildren(this);
    }
  
    /// Check constructor declaration to ensure correct super call placement.
    @override
    void visitConstructorDeclaration(ConstructorDeclaration node) {
  