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