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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 pick_auth(endpoint_context, areq, all=False):
 """ Pick authentication method :param areq: AuthorizationRequest instance :return: A dictionary with the authentication method and its authn class ref """


    acrs = []
    try:
        if len(endpoint_context.authn_broker) == 1:
            return endpoint_context.authn_broker.default()

        if "acr_values" in areq:
            if not isinstance(areq["acr_values"], list):
                areq["acr_values"] = [areq["acr_values"]]
            acrs = areq["acr_values"]
        else:  # same as any
            try:
                acrs = areq["claims"]["id_token"]["acr"]["values"]
            except KeyError:
                try:
                    _ith = areq[verified_claim_name("id_token_hint")]
                except KeyError:
                    try:
                        _hint = areq['login_hint']
                    except KeyError:
                        pass
                    else:
                        if endpoint_context.login_hint2acrs:
                            acrs = endpoint_context.login_hint2acrs(_hint)
                else:
                    try:
                        acrs = [_ith['acr']]
                    except KeyError:
                        pass

                if not acrs:
                    return endpoint_context.authn_broker.default()

        for acr in acrs:
            res = endpoint_context.authn_broker.pick(acr)
            logger.debug("Picked AuthN broker for ACR %s: %s" % (
                str(acr), str(res)))
            if res:
                if all:
                    return res
                else:
                    # Return the first guess by pick.
                    return res[0]

    except KeyError as exc:
        logger.debug(
            "An error occurred while picking the authN broker: %s" % str(exc))

    return None