System.Linq.CachedReflectionInfo.Average_Int64_TSource_2 C# (CSharp) Метод

        public static MethodInfo Average_Int64_TSource_2(Type TSource) =>
             (s_Average_Int64_TSource_2 ??
             (s_Average_Int64_TSource_2 = new Func<IQueryable<object>, Expression<Func<object, long>>, double>(Queryable.Average).GetMethodInfo().GetGenericMethodDefinition()))
              .MakeGenericMethod(TSource);