Class GridValidationBuilder

// Add a grid item to a form and require one response per column. const form = FormApp.create('My Form'); const gridItem = form.addGridItem(); gridItem.setTitle('Rate your interests')     .setRows(['Cars', 'Computers', 'Celebrities'])     .setColumns(['Boring', 'So-so', 'Interesting']); const gridValidation = FormApp.createGridValidation()                            .setHelpText('Select one item per column.')                            .requireLimitOneResponsePerColumn()                            .build(); gridItem.setValidation(gridValidation);