docs: @Nonnull
    public final HCSWFObject addFlashVar (@Nonnull final String sName, final Object aValue)
    {
      if (!JSMarshaller.isJSIdentifier (sName))
        throw new IllegalArgumentException ("The name '" + sName + "' is not a legal JS identifier!");
  
      if (m_aFlashVars == null)
        m_aFlashVars = new CommonsLinkedHashMap <> ();
      m_aFlashVars.put (sName, aValue);
      return this;
    }