docs: public boolean isServletRegistered (@Nonnull final Class <? extends GenericServlet> aServletClass)
    {
      final String sClassName = ValueEnforcer.notNull (aServletClass, "ServletClass").getName ();
  
      // May be null for unit tests
      final IGlobalWebScope aGlobalScope = WebScopeManager.getGlobalScopeOrNull ();
      if (aGlobalScope != null)
      {
        try
        {
          for (final ServletRegistration aRegistration : aGlobalScope.getServletContext ()
                                                                     .getServletRegistrations ()
                                                                     .values ())
            if (aRegistration.getClassName ().equals (sClassName))
              return true;
        }
        catch (final UnsupportedOperationException ex)
        {
          // Happens for mock servlet contexts
        }
      }
      return false;
    }