// 7.3.20 SpeciesConstructor(O, defaultConstructor) var anObject = require('./_an-object'); var aFunction = require('./_a-function'); var SPECIES = require('./_wks')('species'); module.exports = function (O, D) { var C = anObject(O).constructor; var S; return C === undefined || (S = anObject(C)[SPECIES]) == undefined ? D : aFunction(S); };