def METHOD_NAME(processor, test_trace, data_source, peer_service_config):
    processor._set_defaults_enabled = True
    span = test_trace[0]
    span.set_tag(SPAN_KIND, SpanKind.CLIENT)
    span.set_tag(data_source, "test_value")
    processor.process_trace(test_trace)
    assert span.get_tag(peer_service_config.tag_name) == "test_value"
    assert span.get_tag(peer_service_config.source_tag_name) == data_source