/* @flow */

//type Id<T> = (t: T) => T;
//var id: Id<string> = function() {}

type IdObj = {
  id<T>(t: T): T;
}

var ex1: IdObj = {
  id: function<T>() {}
};

var ex3: IdObj = {
  id: function<T>(t):string {
    return t;
  }
};

var a = ex3.id(7);
a;