How to use the zalgo-promise/src.ZalgoPromise.onPossiblyUnhandledException function in zalgo-promise

[FPTI_KEY.SELLER_ID]:              mID && mID[0],
            [FPTI_KEY.SESSION_UID]:            getSessionID(),
            [FPTI_KEY.REFERER]:                window.location.host,
            [FPTI_KEY.LOCALE]:                 `${ lang }_${ country }`,
            [FPTI_KEY.INTEGRATION_IDENTIFIER]: getClientID(),
            [FPTI_KEY.PARTNER_ATTRIBUTION_ID]: getPartnerAttributionID(),
            [FPTI_KEY.SDK_NAME]:               FPTI_SDK_NAME.PAYMENTS_SDK,
            [FPTI_KEY.SDK_VERSION]:            getVersion(),
            [FPTI_KEY.USER_AGENT]:             window.navigator && window.navigator.userAgent,
            [FPTI_KEY.USER_ACTION]:            getCommit() ? FPTI_USER_ACTION.COMMIT : FPTI_USER_ACTION.CONTINUE,
            [FPTI_KEY.CONTEXT_CORRID]:         getCorrelationID(),
            [FPTI_KEY.SDK_INTEGRATION_SOURCE]: getSDKIntegrationSource()
        };
    });

    ZalgoPromise.onPossiblyUnhandledException(err => {

        logger.track({
            [FPTI_KEY.ERROR_CODE]: 'payments_sdk_error',
            [FPTI_KEY.ERROR_DESC]: stringifyErrorMessage(err)
        });

        logger.error('unhandled_error', {
            err: stringifyError(err)
        });

        // eslint-disable-next-line promise/no-promise-in-callback
        logger.flush().catch(noop);
    });

    waitForWindowReady().then(() => {
        const loadTime = getResourceLoadTime(getSDKScript().src);

logger.addPayloadBuilder(function () {
        return {
            referer: window.location.host,
            uid: getSessionID(),
            env: getEnv()
        };
    });

    logger.addTrackingBuilder(function () {
        var _ref;

        return _ref = {}, _ref[FPTI_KEY.FEED] = FPTI_FEED.PAYMENTS_SDK, _ref[FPTI_KEY.DATA_SOURCE] = FPTI_DATA_SOURCE.PAYMENTS_SDK, _ref[FPTI_KEY.CLIENT_ID] = getClientID(), _ref[FPTI_KEY.SELLER_ID] = getMerchantID(), _ref[FPTI_KEY.SESSION_UID] = getSessionID(), _ref[FPTI_KEY.REFERER] = window.location.host, _ref[FPTI_KEY.LOCALE] = getLang() + '_' + getCountry(), _ref[FPTI_KEY.BUYER_COUNTRY] = getCountry(), _ref[FPTI_KEY.INTEGRATION_IDENTIFIER] = getClientID(), _ref[FPTI_KEY.PARTNER_ATTRIBUTION_ID] = getPartnerAttributionID(), _ref[FPTI_KEY.SDK_NAME] = FPTI_SDK_NAME.PAYMENTS_SDK, _ref[FPTI_KEY.SDK_VERSION] = getVersion(), _ref[FPTI_KEY.USER_AGENT] = window.navigator && window.navigator.userAgent, _ref[FPTI_KEY.USER_ACTION] = getCommit() ? FPTI_USER_ACTION.COMMIT : FPTI_USER_ACTION.CONTINUE, _ref[FPTI_KEY.CONTEXT_CORRID] = getCorrelationID(), _ref;
    });

    ZalgoPromise.onPossiblyUnhandledException(function (err) {
        var _logger$track;

        logger.track((_logger$track = {}, _logger$track[FPTI_KEY.ERROR_CODE] = 'checkoutjs_error', _logger$track[FPTI_KEY.ERROR_DESC] = stringifyErrorMessage(err), _logger$track));

        logger.error('unhandled_error', {
            stack: stringifyError(err),
            errtype: {}.toString.call(err)
        });

        // eslint-disable-next-line promise/no-promise-in-callback
        logger.flush()['catch'](noop);
    });
}

/* @flow */

import { logger, FPTI_KEY } from 'paypal-braintree-web-client/src';
import { ZalgoPromise } from 'zalgo-promise/src';
import { stringifyError, stringifyErrorMessage, once } from 'belter/src';

import { CURRENT_ENV } from './globals';
import { checkForCommonErrors, isEligible, setupLogger } from './lib';

ZalgoPromise.onPossiblyUnhandledException(err => {

    logger.error('unhandled_error', {
        stack:   stringifyError(err),
        errtype: ({}).toString.call(err)
    });

    logger.track({
        [ FPTI_KEY.ERROR_CODE ]: 'checkoutjs_error',
        [ FPTI_KEY.ERROR_DESC ]: stringifyErrorMessage(err)
    });

    logger.flush();
});

export let setup = once(() => {

[FPTI_KEY.SESSION_UID]:            sessionID,
            [FPTI_KEY.REFERER]:                window.location.host,
            [FPTI_KEY.MERCHANT_DOMAIN]:        merchantDomain,
            [FPTI_KEY.LOCALE]:                 `${ lang }_${ country }`,
            [FPTI_KEY.INTEGRATION_IDENTIFIER]: clientID,
            [FPTI_KEY.PARTNER_ATTRIBUTION_ID]: partnerAttributionID,
            [FPTI_KEY.SDK_NAME]:               FPTI_SDK_NAME.PAYMENTS_SDK,
            [FPTI_KEY.SDK_VERSION]:            version,
            [FPTI_KEY.USER_AGENT]:             window.navigator && window.navigator.userAgent,
            [FPTI_KEY.USER_ACTION]:            commit ? FPTI_USER_ACTION.COMMIT : FPTI_USER_ACTION.CONTINUE,
            [FPTI_KEY.CONTEXT_CORRID]:         correlationID,
            [FPTI_KEY.BUTTON_VERSION]:         __SMART_BUTTONS__.__MINOR_VERSION__
        };
    });

    ZalgoPromise.onPossiblyUnhandledException(err => {

        logger.track({
            [FPTI_KEY.ERROR_CODE]: 'payments_sdk_error',
            [FPTI_KEY.ERROR_DESC]: stringifyErrorMessage(err)
        });

        logger.error('unhandled_error', {
            err: stringifyError(err)
        });

        // eslint-disable-next-line promise/no-promise-in-callback
        logger.flush().catch(noop);
    });
}