def METHOD_NAME(cryptography_version):
    # cryptography < 1.3.4
    try:
        cryptography_version = list(map(int, cryptography_version.split(".")))
    except ValueError:
        return
    if cryptography_version < [1, 3, 4]:
        warning = "Old version of cryptography ({}) may cause slowdown.".format(
            cryptography_version
        )
        warnings.warn(warning, RequestsDependencyWarning)