code: def test_directly_call_service_with_permission(
      worker, guest_mock_user, update_user
  ):
      root_domain_client = worker.root_client
      user_id = guest_mock_user.id
      api_call = SyftAPICall(
          node_uid=root_domain_client.id,
          path="user.update",
          args=[user_id, update_user],
          kwargs={},
      )
      signed_call = api_call.sign(root_domain_client.api.signing_key)
      signed_result = root_domain_client.api.connection.make_call(
          signed_call
      )
      result = signed_result.message.data
      assert result
  
file_path: PySyft/packages/syft/tests/syft/service_permission_test.py
imports: import pytest
  from syft import SyftError
  from syft.client.api import SyftAPICall
label_desc: Use image node_id 4 for calling a global function with example usage: test_directly_call_service_with_permission(worker, guest_mock_user, update_user) without return types