code: function waitForString(page, ph, str, callback) {
      var elapsed = 0;
      var currentDom = '';
      var timeout = false;
  
      async.until(
          function () {
              timeout = elapsed > constants.WAIT_TIMEOUT;
              return currentDom.indexOf(str) > -1 || timeout;
          },
  
          function (callback) {
              setTimeout(function () {
                  getData.takeSnapshot(page, ph, function (error, page, ph, dom) {
                      if (error) {
                          callback(error);
                          return;
                      }
                      currentDom = dom;
                      elapsed += constants.POLL_INTERVAL;
                      callback();
                  })
              }, constants.POLL_INTERVAL);
          },
  
          function (error) {
              if (error) {
                  callback(error, page, ph);
                  return;
              }
              if (timeout) {
                  callback('Timeout while waiting for string', page, ph);
                  return;
              }
              callback(null, page, ph);
          }
      );
  }
docs: Polls the DOM and wait until a certain string is present
  @param page
  @param ph
  @param str
  @param {pageCallback} callback