code: function createWorld() {
  
      var runtime = {
          driver: null,               // the browser object
          eyes: null,
          selenium: selenium,         // the raw nodejs selenium driver
          By: selenium.By,            // in keeping with Java expose selenium By
          by: selenium.By,            // provide a javascript lowercase version
          until: selenium.until,      // provide easy access to selenium until methods
          expect: expect,             // expose chai expect to allow variable testing
          assert: assert,             // expose chai assert to allow variable testing
          trace: consoleInfo,         // expose an info method to log output to the console in a readable/visible format
          page: global.page || {},    // empty page objects placeholder
          shared: global.shared || {} // empty shared objects placeholder
      };
  
      // expose properties to step definition methods via global variables
      Object.keys(runtime).forEach(function (key) {
          if (key === 'driver' && browserTeardownStrategy !== 'always') {
              return;
          }
  
          // make property/method available as a global (no this. prefix required)
          global[key] = runtime[key];
      });
  }
docs: Creates a list of variables to expose globally and therefore accessible within each step definition
  @returns {void}