const fetchTxDataPromise = (BCH, txidBatch) => {
        return new Promise((resolve, reject) => {
            BCH.Electrumx.txData(txidBatch).then(
                result => {
                    resolve(result);
                },
                err => {
                    return reject(err);
                },
            );
        });
    };

    const fetchTxDataForNullUtxos = async (BCH, nullUtxos) => {
        // Check nullUtxos. If they aren't eToken txs, count them
        console.log(
            `Null utxos found, checking OP_RETURN fields to confirm they are not eToken txs.`,
        );
        const txids = [];
        for (let i = 0; i < nullUtxos.length; i += 1) {
            // Batch API call to get their OP_RETURN asm info
            txids.push(nullUtxos[i].tx_hash);
        }

        // segment the txids array into chunks under the api limit
        const batchedTxids = batchArray(txids, currency.xecApiBatchSize);

        // build an array of promises
        let txDataPromises = [];
        // loop through each batch of 20 txids
        for (let j = 0; j < batchedTxids.length; j += 1) {
            const txidsForThisFetch = batchedTxids[j];
            //console.log(`txidsForThisPromise`, txidsForThisFetch);
            // build the promise for the api call with the 20 txids in current batch
            const thisTxDataPromise = fetchTxDataPromise(
                BCH,
                txidsForThisFetch,
            );
            txDataPromises.push(thisTxDataPromise);
        }

        try {
            const nullUtxoTxData = await Promise.all(txDataPromises);
            // Scan tx data for each utxo to confirm they are not eToken txs
            let thisTxDataResult;
            let nonEtokenUtxos = [];
            for (let k = 0; k < nullUtxoTxData.length; k += 1) {
                thisTxDataResult = nullUtxoTxData[k].transactions;
                nonEtokenUtxos = nonEtokenUtxos.concat(
                    checkNullUtxosForTokenStatus(thisTxDataResult),
                );
            }
            return nonEtokenUtxos;
        } catch (err) {
            console.log(
                `Error in checkNullUtxosForTokenStatus(nullUtxos)` + err,
            );
            console.log(`nullUtxos`, nullUtxos);
            // If error, ignore these utxos, will be updated next utxo set refresh
            return [];
        }
    };