System.Collections.ArrayList.Range.this C# (CSharp) Method

            public override Object this[int index]
            {
                get
                {
                    InternalUpdateRange();
                    if (index < 0 || index >= _baseSize) throw new ArgumentOutOfRangeException(nameof(index), SR.ArgumentOutOfRange_Index);
                    return _baseList[_baseIndex + index];
                }
                set
                {
                    InternalUpdateRange();
                    if (index < 0 || index >= _baseSize) throw new ArgumentOutOfRangeException(nameof(index), SR.ArgumentOutOfRange_Index);
                    _baseList[_baseIndex + index] = value;
                    InternalUpdateVersion();
                }
            }