Here you can find the source of startsWith(prefix)
String.prototype.startsWith = function(prefix) { return this.indexOf(prefix) === 0; };
String.prototype.startsWith = function(pattern) { return (this.substr(0, pattern.length) === pattern); };
String.prototype.startsWith = function (prefix) { return this.indexOf(prefix) === 0; String.prototype.endsWith = function (suffix) { return this.match(suffix + "$") == suffix; };
String.prototype.startsWith = function(prefix){ if(prefix.length > this.length) return false; for(var i = 0; i < prefix.length; i++) if(prefix[i] != this[i]) return false; return true;
'use strict'; String.prototype.startsWith = function (prefix) { return this.indexOf(prefix) === 0; }; function registerPlugin(plugin) { angular.module('flexget').requires.push(plugin.name);
String.prototype.startsWith = function(prefix) { if (!prefix) return false; return this.indexOf(prefix) === 0; };
String.prototype.startsWith = function(prefix) return (this.substr(0, prefix.length) === prefix);
String.prototype.startsWith = function(prefix) { return this.indexOf(prefix) == 0; };
String.prototype.startsWith = function(prefix) { var i = this.indexOf(prefix); if (i == 0) { return true; return false;
String.prototype.startsWith = function (prefix) { "use strict"; if (!prefix && typeof prefix !== 'string') { return false; return this.indexOf(prefix) === 0; };