radio button click in selenium code example

Example 1: how to handle radio button in selenium

- I locate it as just another web element AND CLICK.
    - I would verify if checkbox is selected or not by
        - .isSelected() method will return true if checkbox is selected.
        - .isSelected() method will return false if checkbox is NOT selected.
syntax: checkbox.click();
syntax: checkbox.isSelected(); --> will return boolean: true/false

Example 2: radio buttons selenium

- We locate, and we click on them. 
isSelected() isSelected()--> true,  else --> false 
This method checks if the checkbox/radiobutton is selected or not selected. 
isEnabled() isEnabled -> true,  else --> false
This method checks if the checkbox/radiobutton is enabled to be clicked.      
isDispalyed()  isDispalyed()-> true, else --> false
verify the presence of a web element within the web page.                          

    syntax: driver.findElement(LOCATOR).isSelected();   
    syntax: driver.findElement(LOCATOR).isEnabled();
StaleElementReferenceException: 
A stale element reference exception is thrown in one of two cases
1- The element has been deleted entirely.
2- The element is no longer attached to the DOM.
    WebElement checkbox = driver.findElement(LOCATOR); 
    checkbox.click; driver.navigate().refresh(); 
    checkbox = driver.findElement(LOCATOR);
checkbox.click();  <--stale element reference exception will be thrown