System.Data.ProviderBase.SchemaMapping.RollbackAddedItems C# (CSharp) Method

        private void RollbackAddedItems(List<object> items)
        {
            if (null != items)
            {
                for (int i = items.Count - 1; 0 <= i; --i)
                {
                    // remove columns that were added now that we are failing
                    if (null != items[i])
                    {
                        DataColumn column = (items[i] as DataColumn);
                        if (null != column)
                        {
                            if (null != column.Table)
                            {
                                column.Table.Columns.Remove(column);
                            }
                        }
                        else
                        {
                            DataTable table = (items[i] as DataTable);
                            if (null != table)
                            {
                                if (null != table.DataSet)
                                {
                                    table.DataSet.Tables.Remove(table);
                                }
                            }
                        }
                    }
                }
            }
        }