Switch user sessions using Account Switcher service

Example:

use Drupal\Core\Session\UserSession;

//

// Call the account switcher service

$accountSwitcher = \Drupal::service('account_switcher');

// Switch to the admin user

$accountSwitcher->switchTo(new \Drupal\Core\Session\UserSession(['uid' => 1]));

//

// Your Code Here...

//

// Switch back to old session.

$accountSwitcher->switchBack();