### Question:
OptionDAO { public String get(String optionName) { TransactionalDataSource dataSource = databaseManager.getDataSource(); try (Connection con = dataSource.getConnection()) { PreparedStatement stmt = con.prepareStatement("SELECT * FROM option WHERE name = ?"); stmt.setString(1, optionName); try (ResultSet rs = stmt.executeQuery()) { if (rs.next()) { return rs.getString("value"); } } } catch (SQLException e) { log.error(e.getMessage()); } return null; } @Inject  OptionDAO(DatabaseManager databaseManager); String get(String optionName); boolean set(String optionName, String optionValue); boolean delete(String optionName); void deleteAll(); boolean exist(String optionKey);  }### Answer:
@Test void get() { String value = optionDAO.get("unknown_key_1"); assertNull(value); }