private QueryParameter GetCreateParameter(string name)
 {
   QueryParameter result;
   if (_paramCache.TryGetValue(name, out result))
     return result;
   result = new QueryParameter() { Name = name };
   _paramCache[name] = result;
   return result;
 }
 public void Overwrite(QueryParameter value)
 {
   this.Name = value.Name;
   this.TextValue = value.TextValue;
   this.Type = value.Type;
 }