System.Collections.Hashtable.KeyCollection.CopyTo C# (CSharp) Method

            public virtual void CopyTo(Array array, int arrayIndex)
            {
                if (array == null)
                    throw new ArgumentNullException(nameof(array));
                if (array.Rank != 1)
                    throw new ArgumentException(SR.Arg_RankMultiDimNotSupported, nameof(array));
                if (arrayIndex < 0)
                    throw new ArgumentOutOfRangeException(nameof(arrayIndex), SR.ArgumentOutOfRange_NeedNonNegNum);
                Contract.EndContractBlock();
                if (array.Length - arrayIndex < _hashtable._count)
                    throw new ArgumentException(SR.Arg_ArrayPlusOffTooSmall);
                _hashtable.CopyKeys(array, arrayIndex);
            }