code: public static <T> Position.Writable<T> writable(final Typed<T> typed, Consumer<T> consumer) {
          return writable(Validate.notNull(typed, "type").getType(), consumer);
      }
docs: Get a writable position of type {@code type#value}.
  
  @param typed not {@code null}
  @param consumer not {@code null}
  @return Position.Writable