So siehts ganz gut aus !

node_modules/es5-ext/math/sign/is-implemented.js

@@ -0,0 +1,7 @@
+"use strict";
+
+module.exports = function () {
+	var sign = Math.sign;
+	if (typeof sign !== "function") return false;
+	return (sign(10) === 1) && (sign(-20) === -1);
+};