code: def basic_auth_user(self, realm, user_name, password, environ):
          
          user = self._get_realm_entry(realm, user_name)
  
          if user is not None and password == user.get("password"):
              environ["wsgidav.auth.roles"] = user.get("roles", [])
              return True
          return False
docs: Returns True if this user_name/password pair is valid for the realm,
          False otherwise. Used for basic authentication.