Test if a radio button is unchecked in Nightwatch

radioButtonNotChecked.js

// cribbed from http://www.melkybee.com/blog/2015/07/12/nightwatch-js-check-if-a-checkbox-is-checked/

client.element('id', 'application_partner_over_61_false', function(response) {
  client.elementIdSelected(response.value.ELEMENT, function(result) {
    client.assert.ok(!result.value, 'Radio button #application_partner_over_61_false is not selected');
  });
});

Thanks lot i used below code it worked for me

To check radio button is selected:
.element('css selector', '#pre401kPercent>input', function(response) {
client.elementIdSelected(response.value.ELEMENT, function(result) {
client.assert.ok(result.value, 'Radio button #pre401kPercent is selected');
})
})

To check radio button is not selected:
.element('css selector', '#pre401kDollar>input', function(response) {
client.elementIdSelected(response.value.ELEMENT, function(result) {
client.assert.ok(!result.value, 'Radio button #pre401kDollar is not selected');
})
})