code: @Nonnull
    @ReturnsMutableCopy
    public ICommonsList <CSSMediaRule> getAllMediaRules ()
    {
      return m_aRules.getAllMapped (r -> r instanceof CSSMediaRule, r -> (CSSMediaRule) r);
    }
docs: Get a list of all top-level rules that are media rules (implementing
  {@link CSSMediaRule}).
  
  @return A copy of all contained <code>@media</code> rules. Never
  <code>null</code>.