code: @SuppressWarnings("RedundantTypeArguments")
      public static <A> State<A, A> get() {
          return new State<>(Tuple2::<A>fill);
      }
docs: Create a {@link State} that simply returns back the initial state as both the result and the final state
  
  @param <A> the state and result type
  @return the new {@link State} instance