def get_license(j):
    """
    By default, the license info can be achieved from json["info"]["license"]
    In rare cases it doesn't work.
    We fall back to json["info"]["classifiers"], it looks like License :: OSI Approved :: BSD Clause
    """
    if j["info"]["license"] != "":
        return j["info"]["license"]
    for k in j["info"]["classifiers"]:
        if k.startswith("License"):
            ks = k.split("::")
            return ks[2].strip()
    return ""