def METHOD_NAME(
    client, dmd_version_asthma_medication, dmd_version_asthma_medication_alt_headers
):
    # codelists have identical codes, different CSV headers
    # 2 codes only:
    # 10514511000001106 - Adrenaline (base) 220micrograms/dose inhaler
    # 10525011000001107 - Adrenaline (base) 220micrograms/dose inhaler refill
    rsp = client.get(
        dmd_version_asthma_medication.get_diff_url(
            dmd_version_asthma_medication_alt_headers
        )
    )
    assert rsp.context["common_codes"] == {"10514511000001106", "10525011000001107"}
    assert rsp.context["rhs_only_codes"] == rsp.context["lhs_only_codes"] == set()