text: from flask_login import UserMixin
  from app.firebase_service import get_user
  
  
  class UserData:
      def __init__(self, username, password):
          self.username = username
          self.password = password
  
  class UserModel(UserMixin):
      """
      ;param user_data: UserData
      """
      def __init__(self, user_data):
          self.id = user_data.username
          self.password = user_data.password
          
      @staticmethod
      def query(user_id):
          user_doc = get_user(user_id)
          user_data = UserData(
              username = user_doc.id,
              password=user_doc.to_dict()['password']
          )
          return UserModel(user_data)