text: import os
  from db.tinydb import DB
  
  class UserService:
    def __init__(self):
      self.DB = DB()
      
    def addUser(self, new_user_name: str):
      self.DB.addUser(new_user_name)
      
    def removeUser(self, user_name: str):
      self.DB.removeUser(user_name)
  
    def listUsers(self) -> [str]:
      return self.DB.listUsers()
  
    def isTheOwner(self, update) -> bool:
      user_name = update.message.from_user.name.lower()
      if user_name == os.environ.get('TELEGRAM_OWNER_NAME').lower():
          return True
      else:
          return False
  
    def isAllowedUser(self, update) -> bool:
      user_name = update.message.from_user.name.lower()
      if self.isTheOwner(update):
        return True
      else:
        return self.DB.isAllowedUser(user_name)