title: Unable to find page objects section,what am I missing here?
body: <p>Using Nightwatch's Page Object capability, I have a page of nesting page object sections. When  I run the test 'googleCase.js'</p>
  
  <p>This is the error I'm getting:
  <code>Error: Element "appSection" was not found in "menu". Available elements: mail, images</code></p>
  
  <blockquote>
    <p>environment :nightwatch v1.3.2</p>
  </blockquote>
  
  <p>Code sample：</p>
  
  <p>My page： google.js</p>
  
  <pre><code>module.exports = {
      url: 'https://google.com',
      sections: {
          menu: {
              selector: '#gb',
              elements: {
                  mail: {
                      selector: 'a[href="mail"]'
                  },
                  images: {
                      selector: 'a[href="imghp"]'
                  }
              },
              sections: {
                  apps: {
                      selector: 'div.gb_pc',
                      elements: {
                          myAccount: {
                              selector: '#gb192'
                          },
                          googlePlus: {
                              selector: '#gb119'
                          }
                      }
                  }
              }
          }
      }
  };
  </code></pre>
  
  <p>test: googleCase.js</p>
  
  <pre><code>module.exports = {
      'Test' : function (browser) {
          let google = browser.page.google();
          google.navigate()
          google.expect.section('@menu').to.be.visible;
  
  
          var menuSection = google.section.menu;
          var appSection = menuSection.section.apps;
          menuSection.click('@appSection');
  
          browser.end()
      }
  }
  </code></pre>