def METHOD_NAME(
    self,
    ephemeral_context_with_defaults: EphemeralDataContext,
    new_site_config: dict,
):
    # Check fixture configuration
    existing_site_name = "local_site"
    assert existing_site_name in ephemeral_context_with_defaults.get_site_names()
    with pytest.raises(gx_exceptions.InvalidKeyError) as e:
        new_site_name = existing_site_name
        ephemeral_context_with_defaults.add_data_docs_site(
            site_name=new_site_name, site_config=new_site_config
        )
    assert "Data Docs Site `local_site` already exists in the Data Context." in str(
        e.value
    )