main.dart

import 'dart:async';

class AsyncProxyController<T> {
  
}

class AsyncProxy<T> {
  AsyncProxyController<T> ctrl;
}

typedef Future<V> WithProxyFunction<ProxyT, V>(ProxyT proxy);

class ProxyManager<T, ProxyT extends AsyncProxy<T>> {
    Future<V> doWithProxy<V>(String fnName, WithProxyFunction<ProxyT, V> fn) {
      return fn(proxy);
    }
}


void main() {
}