code: public static boolean isNull(Object object) {
      // don't call nullOf because will throw IllegalArgumentException if cannot create instance
      return object != null && object == NULL_CACHE.get(object.getClass());
    }
docs: Returns whether the given object is the magic object that represents the null value of its
  class.
  
  @param object object or {@code null}
  @return whether it is the magic null value or {@code false} for {@code null} input