code: public function iSwitchToWindow()
      {
          $windows = $this->getWindowNames();
  
          // If the window was not switched yet, then store it name and working element for future switching back.
          if (empty($this->mainWindow)) {
              $this->mainWindow['name'] = array_shift($windows);
              $this->mainWindow['element'] = $this->getWorkingElement();
  
              $window = reset($windows);
          } else {
              $window = $this->mainWindow['name'];
              $element = $this->mainWindow['element'];
  
              $this->mainWindow = [];
          }
  
          $this->getSession()->switchToWindow($window);
          $this->setWorkingElement(isset($element) ? $element : $this->getBodyElement());
      }
docs: Supports switching between the two windows only.
  
  @Given /^(?:|I )switch to opened window$/
  @Then /^(?:|I )switch back to main window$/