code: @SuppressWarnings({"deprecation", "WeakerAccess"})
      protected boolean isFlagPresent(final AttributeAccess.Flag flag) {
          if (flags == null) { return false; }
          for (AttributeAccess.Flag f : flags) {
              if (f.equals(flag)) { return true; }
          }
          return false;
      }
docs: Checks if a {@link AttributeAccess.Flag special purpose flag} has been recorded as relevant to the attribute
  @param flag the flag
  @return a builder that can be used to continue building the attribute definition