title: access to private attribute in abstract class dart
body: <p>I need access to private attribute in abstract class inside flutter SDK. I reduce my problem to this case:</p>
  
  <pre><code>abstract class Person{
    final String _name = "Testing...";
  }
  
  class Employee extends Person{
    String get name =&gt;_name;
  }
  
  main(){
    var emp = new Employee();
    print(emp.name);
  }
  </code></pre>
  
  <p>If I put the Person class and the Employee class in the same .dart file, I can access the private attribute _name in Person from Employee, but I can't do the same if I move Person class to another .dart file.</p>
  
  <p>dart documentation says: If an identifier starts with an underscore _ , it's private to its library. Libraries not only provide APIs, but are a unit of privacy: identifiers that start with an underscore _ are visible only inside the library. </p>
  
  <p>How can I make them belong to the same library when they are in different files?</p>