title: Is there any *? operator in dart?
body: <p>Is there any <code>*?</code> operator in dart?</p>
  <p>I am using <code>copy_with_extension</code> to generate codes, Currently I have error like</p>
  <pre><code>[SEVERE] copy_with_extension_gen:copy_with_extension_gen on lib/models/my_model.dart:
  An error `FormatterException` occurred while formatting the generated source for
    `package:app/models/my_model.dart`
  which was output to
    `lib/models/my_model.copyWith.g.part`.
  This may indicate an issue in the generator, the input source code, or in the
  source formatter.
  Could not format because the source could not be parsed:
  
  line 8, column 51 of .: Expected to find '}'.
    ╷
  8 │               MyModel copyWith({ String*? myField})
  {
    │                                                   ^
    ╵
  
  </code></pre>
  <p><code>*?</code> is weird , <code>?</code> is for nullable , What is <code>*</code> ?</p>
  <p>As I am using <code>sdk: &quot;&gt;=2.7.0 &lt;3.0.0&quot;</code> and too busy to migrate null safety, I want to fork and change to unsound null safety</p>