code: @Nullable
    @OverrideOnDemand
    protected IHCElement <?> createSingleErrorNode (@Nonnull final IError aError, @Nonnull final Locale aContentLocale)
    {
      return BootstrapFormHelper.createDefaultErrorNode (aError, aContentLocale);
    }
docs: Create the node for a single error.
  
  @param aError
  The provided error. Never <code>null</code>.
  @param aContentLocale
  Locale to be used to show error text.
  @return May be <code>null</code>.