public void Add_new_transaction_to_savings(DateTime new_date, double new_amount) { var sheet_name = MainSheetNames.Savings; int first_column_number = 1; int row_number = _spreadsheet_io.Find_first_empty_row_in_column(sheet_name, first_column_number); _spreadsheet_io.Update_date(sheet_name, row_number, first_column_number, new_date); _spreadsheet_io.Update_amount(sheet_name, row_number, first_column_number + 1, new_amount); }