Zombie.js negation selector

Currently have been doing some UI tests with Zombie.js framework and cannot find on their documentation on negating selectors.

Simple test to run with mocha is:

const Browser = require('zombie');
Browser.localhost('127.0.0.1', 80);

describe('user visits ', function () {    
  const browser = new Browser();

  before(done => {
    browser.visit('/index.html', done);
  });

  describe('page', () => {
    it('should being open', () => {
      browser.assert.success();
    });

    it('has class "header__logo" assigned', () => {
      browser.assert.hasClass('p', 'header__logo');
    });

});

Code

browser.assert.not.hasClass('p', 'header__logo');

doesn't seem to be working.

What way can I negate having a class header__logo ?