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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_trace_id():
 """Helper to get trace_id from web application request header. :rtype: str :returns: TraceID in HTTP request headers. """

    checkers = (
        get_trace_id_from_django,
        get_trace_id_from_flask,
        get_trace_id_from_webapp2,
    )

    for checker in checkers:
        trace_id = checker()
        if trace_id is not None:
            return trace_id

    return None