old_contents: from flask import Response
  
  from flask_login import login_user
  from server.models import User
  from server.login_manager import login_manager
  
  
  @login_manager.user_loader
  def load_user(user_id):
      """Returns a user from the database based on their id"""
      return User.query.filter_by(id=user_id).first()
  
  
  def handle_basic_auth(request):
      auth = request.authorization
      if not auth:
          return None
      return User.query.filter_by(
          username=auth.username,
          password=auth.password
      ).first()
  
  
  def login(request):
      """Handle a login request from a user."""
      user = handle_basic_auth(request)
      if user:
          login_user(user, remember=True)
          return 'OK'
      return Response(
          'Could not verify your access level for that URL.\n'
          'You have to login with proper credentials', 401,
          {'WWW-Authenticate': 'Basic realm="Login Required"'})
  
new_contents: import flask
  from flask_login import login_user
  from server.models import User
  from server.login_manager import login_manager
  
  
  @login_manager.user_loader
  def load_user(user_id: int) -> User:
      """Returns a user from the database based on their id
  
      :param user_id: a users unique id
      :return: User object with corresponding id, or none if user does not exist
      """
      return User.query.filter_by(id=user_id).first()
  
  
  def handle_basic_auth(request: flask.Request) -> User:
      """Verifies a request using BASIC auth
  
      :param request: flask request object
      :return: User object corresponding to login information, or none if user does not exist
      """
      auth = request.authorization
      if not auth:
          return None
      return User.query.filter_by(
          username=auth.username,
          password=auth.password
      ).first()
  
  
  def login(request: flask.Request) -> flask.Response:
      """Handle a login request from a user
  
      :param request: incoming request object
      :return: flask response object
      """
      user = handle_basic_auth(request)
      if user:
          login_user(user, remember=True)
          return 'OK'
      return flask.Response(
          'Could not verify your access level for that URL.\n'
          'You have to login with proper credentials', 401,
          {'WWW-Authenticate': 'Basic realm="Login Required"'})
  
subject: Add type declartions and docstrings