title: Referencing to property from another property
body: <p>I've tried but couldn't find a way to reference one property from another, like this:</p>
  
  <pre><code>class Test {
    String prop1;
    String prop2;
  
    Test({this.prop1, this.prop2});
  }
  
  void main() {
    var test = Test(
      prop1: 'some text',
      // and here I want to reference to prop1 but this code is erroneous:
      prop2: '$prop1',
    );
  </code></pre>
  
  <p>Is there any way for it (like "this" in JS)?</p>