code: def test_user_create_invalid_username(invalid_username: str):
      with pytest.raises(ValidationError):
          UserCreate(
              first_name="first-name",
              username=invalid_username,
              password="12345678",
          )
  
imports: from typing import Union
  import pytest
  from argilla.server.security.model import User, UserCreate, WorkspaceCreate
  from tests.factories import UserFactory, WorkspaceFactory
  from tests.pydantic_v1 import ValidationError
label_desc: Use image node_id 2 for calling a global function with example usage: test_user_create_invalid_username(invalid_username) without return types