code: def test_update_schema():
      class UnitTestUpdateSchema(UpdateSchema):
          unit: Optional[str]
          test: Optional[bool]
  
          __non_nullable_fields__ = {"unit", "test"}
  
      with pytest.raises(ValueError):
          UnitTestUpdateSchema(unit=None, test=None)
  
imports: from typing import Optional
  import pytest
  from argilla.server.schemas.base import UpdateSchema
label_desc: Use image node_id 1 for calling a global function with example usage: test_update_schema() without return types