static IEnumerable<MethodInfo> GetExtensionMethods(Assembly assembly, Type extendedType)
         {
             var query = from type in assembly.GetTypes()
                         where !type.IsGenericType && !type.IsNested
                         from method in type.GetMethods(BindingFlags.Static
                             | BindingFlags.Public | BindingFlags.NonPublic)
                         where method.IsDefined(typeof(System.Runtime.CompilerServices.ExtensionAttribute), false)
                         ].ParameterType == extendedType
                         select method;
             return query;
         }