How to use the pouchdb-merge.isLocalId function in pouchdb-merge

stores.bySeqStore.get(seq, function (err, resp) {
            /* istanbul ignore if */
            if (err || !pouchdbMerge.isLocalId(resp._id)) {
              return next();
            }
            batches.push({
              key: seq,
              prefix: stores.bySeqStore,
              type: 'del'
            });
            next();
          });
        }, function () {

cursor.onsuccess = function (event) {
      var cursor = event.target.result;
      if (cursor) {
        var metadata = cursor.value;
        var docId = metadata.id;
        var local = isLocalId(docId);
        var rev = calculateWinningRev(metadata);
        if (local) {
          var docIdRev = docId + "::" + rev;
          // remove all seq entries
          // associated with this docId
          var start = docId + "::";
          var end = docId + "::~";
          var index = seqStore.index('_doc_id_rev');
          var range = IDBKeyRange.bound(start, end, false, false);
          var seqCursor = index.openCursor(range);
          seqCursor.onsuccess = function (e) {
            seqCursor = e.target.result;
            if (!seqCursor) {
              // done
              docStore.delete(cursor.primaryKey);
              cursor.continue();

docInfos.forEach(function (currentDoc, resultsIdx) {

    if (currentDoc._id && isLocalId(currentDoc._id)) {
      var fun = currentDoc._deleted ? '_removeLocal' : '_putLocal';
      api[fun](currentDoc, {ctx: tx}, function (err, res) {
        results[resultsIdx] = err || res;
        checkAllDocsDone();
      });
      return;
    }

    var id = currentDoc.metadata.id;
    if (idsToDocs.has(id)) {
      docsToDo--; // duplicate
      idsToDocs.get(id).push([currentDoc, resultsIdx]);
    } else {
      idsToDocs.set(id, [[currentDoc, resultsIdx]]);
    }
  });

AbstractPouchDB.prototype.get = adapterFun('get', function (id, opts, cb) {
  if (typeof opts === 'function') {
    cb = opts;
    opts = {};
  }
  if (typeof id !== 'string') {
    return cb(createError(INVALID_ID));
  }
  if (isLocalId(id) && typeof this._getLocal === 'function') {
    return this._getLocal(id, cb);
  }
  var leaves = [], self = this;

  function finishOpenRevs() {
    var result = [];
    var count = leaves.length;
    /* istanbul ignore if */
    if (!count) {
      return cb(null, result);
    }

    // order with open_revs is unspecified
    leaves.forEach(function (leaf) {
      self.get(id, {
        rev: leaf,

AbstractPouchDB.prototype.get = adapterFun('get', function (id, opts, cb) {
  if (typeof opts === 'function') {
    cb = opts;
    opts = {};
  }
  if (typeof id !== 'string') {
    return cb(createError(INVALID_ID));
  }
  if (isLocalId(id) && typeof this._getLocal === 'function') {
    return this._getLocal(id, cb);
  }
  var leaves = [], self = this;

  function finishOpenRevs() {
    var result = [];
    var count = leaves.length;
    /* istanbul ignore if */
    if (!count) {
      return cb(null, result);
    }

    // order with open_revs is unspecified
    leaves.forEach(function (leaf) {
      self.get(id, {
        rev: leaf,

AbstractPouchDB.prototype.put = adapterFun('put', function (doc, opts, cb) {
  if (typeof opts === 'function') {
    cb = opts;
    opts = {};
  }
  if (typeof doc !== 'object' || Array.isArray(doc)) {
    return cb(createError(NOT_AN_OBJECT));
  }
  invalidIdError(doc._id);
  if (isLocalId(doc._id) && typeof this._putLocal === 'function') {
    if (doc._deleted) {
      return this._removeLocal(doc, cb);
    } else {
      return this._putLocal(doc, cb);
    }
  }
  var self = this;
  if (opts.force && doc._rev) {
    transformForceOptionToNewEditsOption();
    putDoc(function (err) {
      var result = err ? null : {ok: true, id: doc._id, rev: doc._rev};
      cb(err, result);
    });
  } else {
    putDoc(cb);
  }

}).pipe(through2.obj(function (ch, _, next) {
          if (!pouchdbMerge.isLocalId(ch.key)) {
            return next();
          }
          batches.push({
            key: ch.key,
            prefix: stores.docStore,
            type: 'del'
          });
          var winner = pouchdbMerge.winningRev(ch.value);
          Object.keys(ch.value.rev_map).forEach(function (key) {
            if (key !== 'winner') {
              this.push(formatSeq(ch.value.rev_map[key]));
            }
          }, this);
          var winningSeq = ch.value.rev_map[winner];
          stores.bySeqStore.get(formatSeq(winningSeq), function (err, value) {
            if (!err) {

}).pipe(through(function (ch, _, next) {
          if (!isLocalId(ch.key)) {
            return next()
          }
          batches.push({
            key: ch.key,
            prefix: stores.docStore,
            type: 'del'
          })
          var winner = winningRev(ch.value)
          Object.keys(ch.value.rev_map).forEach(function (key) {
            if (key !== 'winner') {
              this.push(formatSeq(ch.value.rev_map[key]))
            }
          }, this)
          var winningSeq = ch.value.rev_map[winner]
          stores.bySeqStore.get(formatSeq(winningSeq), function (err, value) {
            if (!err) {

}).pipe(through(function (ch, _, next) {
          if (!isLocalId(ch.key)) {
            return next();
          }
          batches.push({
            key: ch.key,
            prefix: stores.docStore,
            type: 'del'
          });
          var winner = winningRev(ch.value);
          Object.keys(ch.value.rev_map).forEach(function (key) {
            if (key !== 'winner') {
              this.push(formatSeq(ch.value.rev_map[key]));
            }
          }, this);
          var winningSeq = ch.value.rev_map[winner];
          stores.bySeqStore.get(formatSeq(winningSeq), function (err, value) {
            if (!err) {

AbstractPouchDB.prototype.put = adapterFun('put', function (doc, opts, cb) {
  if (typeof opts === 'function') {
    cb = opts;
    opts = {};
  }
  if (typeof doc !== 'object' || Array.isArray(doc)) {
    return cb(createError(NOT_AN_OBJECT));
  }
  invalidIdError(doc._id);
  if (isLocalId(doc._id) && typeof this._putLocal === 'function') {
    if (doc._deleted) {
      return this._removeLocal(doc, cb);
    } else {
      return this._putLocal(doc, cb);
    }
  }
  if (typeof this._put === 'function' && opts.new_edits !== false) {
    this._put(doc, opts, cb);
  } else {
    this.bulkDocs({docs: [doc]}, opts, yankError(cb));
  }
});