async def test_022_(http_client, parameter):
    """
    MUST allow null variables/operationName/extensions parameter when accepting application/json
    """
    response = await http_client.post(
        url="/graphql",
        headers={
            "Content-Type": "application/json",
            "Accept": "application/json",
        },
        json={
            "query": "{ __typename }",
            parameter: None,
        },
    )
    assert response.status_code == 200
    assert "errors" not in response.json

    MUST allow null variables/operationName/extensions parameter when accepting application/json
    
tests/http/test_graphql_over_http_spec.py