How to use the web3-core-promievent.resolve function in web3-core-promievent

var checkConfirmation = function (existingReceipt, isPolling, err, blockHeader, sub) {
        if (!err) {
            // create fake unsubscribe
            if (!sub) {
                sub = {
                    unsubscribe: function () {
                        clearInterval(intervalId);
                    }
                };
            }
            // if we have a valid receipt we don't need to send a request
            return (existingReceipt ? promiEvent.resolve(existingReceipt) : _ethereumCall.getTransactionReceipt(result))
            // catch error from requesting receipt
            .catch(function (err) {
                sub.unsubscribe();
                promiseResolved = true;
                utils._fireError({message: 'Failed to check for transaction receipt:', data: err}, defer.eventEmitter, defer.reject);
            })
            // if CONFIRMATION listener exists check for confirmations, by setting canUnsubscribe = false
            .then(function(receipt) {
                if (!receipt || !receipt.blockHash) {
                    throw new Error('Receipt missing or blockHash null');
                }

                // apply extra formatters
                if (method.extraFormatters && method.extraFormatters.receiptFormatter) {
                    receipt = method.extraFormatters.receiptFormatter(receipt);
                }