def METHOD_NAME(samp_eve):
    value = "value"
    header_without_prefix = f"{HOST}={value}_1 header={value}_2"
    event_body = "event body"
    event, metadata, key_fields = samp_eve.update_metadata(
        f"***SPLUNK*** {header_without_prefix}\n{event_body}",
        {HOST: f"{HOST}_{value}"},
        {},
    )
    assert event == event_body
    assert metadata == {HOST: f"{HOST}_{HOST}_{value}", "header": f"{value}_2"}
    assert key_fields == {HOST: [f"{HOST}_{HOST}_{value}"]}