var lo = require('lodash');

  function build_blank(n) {
     var ret = "1"
     for (var i = 0; i < n; i++) {
         ret += " "
     }
     return ret + "1";
 }
 var s = build_blank(50000) var time0 = Date.now();
 lo.trim(s)
 var time_cost0 = Date.now() - time0;
 console.log("time_cost0: " + time_cost0);
 var time1 = Date.now();
 lo.toNumber(s) var time_cost1 = Date.now() - time1;
 console.log("time_cost1: " + time_cost1);
 var time2 = Date.now();
 lo.trimEnd(s);
 var time_cost2 = Date.now() - time2;
 console.log("time_cost2: " + time_cost2);