Nearsoft\SeleniumClient\By::id PHP Method

    public static function id($selectorValue)
    {
        return new By("id", $selectorValue);
    }

 public function testDemo2()
 {
     //click button/get alert text
     $this->_driver->get($this->_testUrl);
     $this->_driver->findElement(By::id("btnAlert"))->click();
     $alert = $this->_driver->switchTo()->alert();
     $this->assertEquals("Here is the alert", $alert->getText());
     $alert->accept();
     //get main window handle
     $mainWindowHandle = $this->_driver->getWindowHandle();
     //open popup window / handle its elements
     $this->_driver->findElement(By::id("btnPopUp1"))->click();
     $this->_driver->switchTo()->window("popup1");
     $webElement = $this->_driver->waitForElementUntilIsPresent(By::id("txt1"));
     $webElement->sendKeys("test window");
     $this->assertEquals("test window", $webElement->getAttribute("value"));
     $this->_driver->close();
     $this->_driver->switchTo()->window($mainWindowHandle);
     //get iframe / handle its elements
     $this->_driver->switchTo()->frame("iframe1");
     $webElement = $this->_driver->waitForElementUntilIsPresent(By::id("txt1"));
     $webElement->sendKeys("test iframe");
     $this->assertEquals("test iframe", $webElement->getAttribute("value"));
     $this->_driver->switchTo()->window($mainWindowHandle);
     //wait for element to be present
     $this->_driver->findElement(By::id("btnAppendDiv"))->click();
     $wait = new WebDriverWait(8);
     $label = $wait->until($this->_driver, "findElement", array(By::id("dDiv1-0"), true));
     $this->assertEquals("Some content", $label->getText());
     sleep(5);
 }