protected void ValidParameterAttribute(bool feature, TimedTextAttributeBase attribute, string value)
        {
            string baseUri = (Parent as ParameterElement).BaseAttributeValue();
            string key     = baseUri + value;

            switch (attribute.LocalName)
            {
            case "value":
                if (feature)
                {
                    if (Features.ContainsKey(key))
                    {
                        Features[key] |= attribute.Value == "required";
                    }
                    else
                    {
                        Features[key] = attribute.Value == "required";
                    }
                }
                else
                {
                    if (Extensions.ContainsKey(key))
                    {
                        Extensions[key] |= attribute.Value == "required";
                    }
                    else
                    {
                        Extensions[key] = attribute.Value == "required";
                    }
                }
                break;

            default:
                Error("Erroneous parameter attribute " + attribute.LocalName + " on " + this.ToString());
                break;
            }
            ;
        }
 protected void ValidParameterAttribute(bool feature, TimedTextAttributeBase attribute, string value)
 {
     string baseUri = (Parent as ParameterElement).BaseAttributeValue();
     string key = baseUri + value;
     switch (attribute.LocalName)
     {
         case "value":
             if (feature)
             {
                 if (Features.ContainsKey(key))
                 {
                     Features[key] |= attribute.Value == "required";
                 }
                 else
                 {
                     Features[key] = attribute.Value == "required";
                 }
             }
             else
             {
                 if (Extensions.ContainsKey(key))
                 {
                     Extensions[key] |= attribute.Value == "required";
                 }
                 else
                 {
                     Extensions[key] = attribute.Value == "required";
                 }
             }
             break;
         default:
             Error("Erroneous parameter attribute " + attribute.LocalName + " on " + this.ToString());
             break;
     };
 }