CheckboxValidationBuilder

A DataValidationBuilder for a `https://developers.google.com/apps-script/reference/forms/checkbox-validation`.

```javascript
// Add a checkBox item to a form and require exactly two selections.
const form = FormApp.create('My Form');
const checkBoxItem = form.addCheckboxItem();
checkBoxItem.setTitle('What two condiments would you like on your hot dog?');
checkBoxItem.setChoices([
  checkBoxItem.createChoice('Ketchup'),
  checkBoxItem.createChoice('Mustard'),
  checkBoxItem.createChoice('Relish'),
]);
const checkBoxValidation = FormApp.createCheckboxValidation()
                               .setHelpText('Select two condiments.')
                               .requireSelectExactly(2)
                               .build();
checkBoxItem.setValidation(checkBoxValidation);
```

### Methods

| Method | Return type | Brief description |
|---|---|---|
| `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#requireSelectAtLeast(Integer)` | `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#` | Require at least this many choices to be selected. |
| `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#requireSelectAtMost(Integer)` | `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#` | Require at most this many choices to be selected. |
| `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#requireSelectExactly(Integer)` | `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#` | Require exactly this many choices to be selected. |

## Detailed documentation

### `requireSelectAtLeast(number)`

Require at least this many choices to be selected.

#### Parameters

| Name | Type | Description |
|---|---|---|
| `number` | `Integer` |   |

#### Return


`https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#` --- this `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#`, for chaining

*** ** * ** ***

### `requireSelectAtMost(number)`

Require at most this many choices to be selected.

#### Parameters

| Name | Type | Description |
|---|---|---|
| `number` | `Integer` |   |

#### Return


`https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#` --- this `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#`, for chaining

*** ** * ** ***

### `requireSelectExactly(number)`

Require exactly this many choices to be selected.

#### Parameters

| Name | Type | Description |
|---|---|---|
| `number` | `Integer` |   |

#### Return


`https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#` --- this `https://developers.google.com/apps-script/reference/forms/checkbox-validation-builder#`, for chaining