public static class ClassExtensions  {    public static TResult GetProperty<TClass, TResult>(this TClass obj, Func<TClass, TResult> func) where TClass : class    {      if ((object) obj == null)        return default (TResult);      else        return func(obj);    }    public static TResult GetProperty<TKey, TResult>(this IDictionary<TKey, TResult> dict, TKey key)    {      if (dict == null || !dict.ContainsKey(key))        return default (TResult);      else        return dict[key];    }    public static TResult GetProperty<TKey, TValue, TResult>(this IDictionary<TKey, TValue> dict, TKey key, Func<TValue, TResult> func)    {      if (dict == null || !dict.ContainsKey(key))        return default (TResult);      TValue obj = dict[key];      return func(obj);    }