in static/js/tracker.js [2289:2302]
e.exports = function (e) {
return function (n, t, u) {
var a,
c = r(n),
s = o(c.length),
f = i(u, s);
if (e && t != t) {
for (; s > f; ) if ((a = c[f++]) != a) return !0;
} else
for (; s > f; f++)
if ((e || f in c) && c[f] === t) return e || f || 0;
return !e && -1;
};
};