title: Forwarding a list.map call: How to specify return type flexibly?
body: <p>I have a class, <code>A</code>, which is backed by a list. I want to be able to forward some calls, somewhat like so:</p>
  <pre><code>class A {
    List&lt;Obj&gt; list;
    Iterable&lt;T&gt; map(Function(Obj) f) =&gt; list.map(f);
  }
  </code></pre>
  <p>However, that <code>Iterable&lt;T&gt;</code> return type obviously doesn't work. I don't want to hardcode a return type here though, as it depends on the given function f. How do I specify my return type to be the same as the one of the argument, <code>f</code>?</p>