code: def test_list_user(store):
      username1 = "1" + random_str()
      password1 = "1" + random_str()
      _user_maker(store, username1, password1)
  
      username2 = "2" + random_str()
      password2 = "2" + random_str()
      _user_maker(store, username2, password2)
  
      username3 = "3" + random_str()
      password3 = "3" + random_str()
      _user_maker(store, username3, password3)
  
      users = store.list_users()
      users.sort(key=lambda u: u.username)
  
      assert len(users) == 3
      assert isinstance(users[0], User)
      assert users[0].username == username1
      assert users[1].username == username2
      assert users[2].username == username3
  
imports: import pytest
  from mlflow.exceptions import MlflowException
  from mlflow.protos.databricks_pb2 import INVALID_PARAMETER_VALUE, RESOURCE_ALREADY_EXISTS, RESOURCE_DOES_NOT_EXIST, ErrorCode
  from mlflow.server.auth.entities import ExperimentPermission, RegisteredModelPermission, User
  from mlflow.server.auth.permissions import ALL_PERMISSIONS, EDIT, READ
  from mlflow.server.auth.sqlalchemy_store import SqlAlchemyStore
  from tests.helper_functions import random_str
label_desc: Use image node_id 8 for calling a global function with example usage: test_list_user(store) without return types