void FillFontFaceDeclarations(CssFontFaceRule rule)
        {
            var token = _tokenizer.Get();

            while (token.IsNot(CssTokenType.Eof, CssTokenType.CurlyBracketClose))
            {
                var property = CreateDeclarationWith(CreateProperty, ref token);

                if (property != null && property.HasValue)
                    rule.SetProperty(property);
            }
        }