code: public function delete_cookie($name) {
          // Remove the cookie
          unset($_COOKIE[$name]);
  
          // Nullify the cookie and make it expire
          return setcookie($name, null, -86400, $this->cookie_path, $this->cookie_domain, $this->cookie_secure, $this->cookie_httponly);
      }
docs: Deletes a cookie by making the value null and expiring it.
  
  Cookie::delete('theme');
  
  @param   string $name cookie name
  @return  boolean