def create_fields(instance, **kwargs):
    """Return dict of fields to be used as create params."""
    site = kwargs.pop("site", instance.site)
    creation_user = kwargs.pop("creation_user", instance.creation_user)
    effective_user = kwargs.pop("effective_user", instance.effective_user)
    update_user = kwargs.pop("update_user", instance.update_user)
    params = dict(
        creation_user=creation_user, effective_user=effective_user,
        site=site, update_user=update_user)
    params.update(kwargs)
    return params