async/src/main/java/com/stanfy/enroscar/async/Tools.java
public static <D> Async<D> async(final Executor executor, final Callable<D> task) {
    return new TaskAsync<>(task, executor);
  }
public static <D> Async<D> async(final Executor executor, final Callable<D> task) {
    return new TaskAsync<>(task, executor);
  }
Create an asynchronous operation that executes a provided task creating
an Android's {@link android.os.AsyncTask} with a specified executor.
@param task job to do
@param executor executor used by AsyncTask
@param <D> result data type
@return implementations of {@link Async}, never {@code null}