@IBAction func loginButtonPressed(_ sender: Any) {
    guard let username = usernameTextField.text, let password = passwordTextField.text, username.count > 0, password.count > 0 else {
      return
    }
    APIClient.login(withUsername: usernameTextField.text!, password: passwordTextField.text!, completion: {
      if UserDefaults.standard.string(forKey: "access_token") != nil {
        let storyboard = UIStoryboard(name: "SchoolsListViewController", bundle: nil)
        let controller = storyboard.instantiateViewController(withIdentifier: "SchoolsListViewController") as! SchoolsListViewController
        self.present(controller, animated: true, completion: nil)
      }
    })
  }