Tracing multi request

[manhtd98]

I set headers[0] the Attr to tracing request. How to trace when I have multi request

def extract_zipkin_attrs(headers):
    if isinstance(headers, list):
        return ZipkinAttrs(
            headers[0],
            generate_random_64bit_string(),
            headers[2],
            headers[3],
            headers[4],
        )
    else:
        return create_attrs_for_span()