code: public RxLoader2<A, B, T> start(A arg1, B arg2) {
          start(observableFunc.call(arg1, arg2));
          return this;
      }
docs: Starts the {@link rx.Observable} with the given arguments.
  
  @param arg1 the first argument
  @param arg2 the second argument
  @return the {@code RxLoader2} for chaining
  @see RxLoader#start()