def canonicalize_baggage_key(key):
    if _baggage_key_re.match(key) is not None:
        return key.lower()
    return None
Write string s to stream.
dataset/ETHPy150Open opentracing/opentracing-python/opentracing/span.py/canonicalize_baggage_key--crossover with--dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/_pyio.py/TextIOBase.write