ExcelDna.Integration.ExcelReference.GetHashCode C# (CSharp) Method

        public override int GetHashCode()
        {
            // One of the ideas from http://stackoverflow.com/questions/263400/what-is-the-best-algorithm-for-an-overridden-system-object-gethashcode
            const int b = 378551;
            int a = 63689;
            int hash = 0;

            unchecked
            {
                for (int i = 0; i < rectangles.Count; i++)
                {
                    if (rectangles[i] != null)
                    {
                        hash = hash * a + rectangles[i].GetHashCode();
                        a = a * b;
                    }
                }
                hash *= 397;
            }
            return hash ^ sheetId.GetHashCode();
        }