code: function asyncRemoveDuplicates(arr) {
      return asyncArray(when(arr).chain(function (result) {
          return removeDuplicates.call(array, normalizeResult(result));
      }));
  }
docs: Async version of {@link comb.array.removeDuplicates}.
  
  ```
  function asyncArr(){
  var ret = new comb.Promise();
  process.nextTick(ret.callback.bind(ret, [1,2,2,3,3,3,4,4,4]);
  return ret.promise;
  }
  
  comb.async.array(asyncArr()).removeDuplicates().then(function(unique){
  console.log(unique); // [1, 2, 3, 4]
  });
  
  comb.async.removeDuplicates(asyncArray()).then(function(unique){
  console.log(unique); // [1, 2, 3, 4]
  });
  ```
  
  @static
  @memberof comb.async
  @name removeDuplicates