Dojo: How to validate checkbox with dojox.validate.check?

I've got checkbox with label that is generated by JSON, but I stucked with its validation. If the checkbox is required what is the right way of validating the checkbox with dojo?

 <div data-tool-element="checkbox" data-tool-element-id="sampleCheckbox" data-tool-element-name="checkboxName" data-tool-element-label="Checkbox label content">
 <label for="checkboxName" data-validation-checkbox="Checkbox is required.">
 <input id="sampleCheckbox" name="checkboxName" type="checkbox"><span>Checkbox label content</span>

if (rule.checkbox) {
  var input = query(element)[0].value
    , checkboxMessage = domAttr.get(query(element)[0], 'data-validation-checkbox')
    , checkboxValid = validate.check(input, "checked");

 if (!checkboxValid) {

    // Highlight the current element and it's label
       domClass.add(element[0], 'errorBorder');
       label.length > 0 && domClass.add(label[0], 'errorColor');

    // Display the error message
       domConstruct.create('div',
        {
          class: 'error',
          innerHTML: checkboxMessage
        }, query(element)[0], 'after');
}