System.Collections.Specialized.NameObjectCollectionBase.KeysCollection.ICollection C# (CSharp) Method

            void ICollection.CopyTo(Array array, int index)
            {
                if (array == null)
                {
                    throw new ArgumentNullException(nameof(array));
                }

                if (array.Rank != 1)
                {
                    throw new ArgumentException(SR.Arg_MultiRank, nameof(array));
                }

                if (index < 0)
                {
                    throw new ArgumentOutOfRangeException(nameof(index), index, SR.ArgumentOutOfRange_NeedNonNegNum);
                }

                if (array.Length - index < _coll.Count)
                {
                    throw new ArgumentException(SR.Arg_InsufficientSpace);
                }

                for (IEnumerator e = this.GetEnumerator(); e.MoveNext();)
                    array.SetValue(e.Current, index++);
            }