So siehts ganz gut aus !

node_modules/es5-ext/number/is-safe-integer/implement.js

@@ -0,0 +1,8 @@
+"use strict";
+
+if (!require("./is-implemented")()) {
+	Object.defineProperty(Number, "isSafeInteger", { value: require("./shim"),
+		configurable: true,
+enumerable: false,
+writable: true });
+}

node_modules/es5-ext/number/is-safe-integer/index.js

@@ -0,0 +1,5 @@
+"use strict";
+
+module.exports = require("./is-implemented")()
+	? Number.isSafeInteger
+	: require("./shim");

node_modules/es5-ext/number/is-safe-integer/is-implemented.js

@@ -0,0 +1,8 @@
+"use strict";
+
+module.exports = function () {
+	var isSafeInteger = Number.isSafeInteger;
+	if (typeof isSafeInteger !== "function") return false;
+	return !isSafeInteger("23") && isSafeInteger(34232322323) &&
+			!isSafeInteger(9007199254740992);
+};

node_modules/es5-ext/number/is-safe-integer/shim.js

@@ -0,0 +1,11 @@
+"use strict";
+
+var isInteger = require("../is-integer/shim")
+  , maxValue  = require("../max-safe-integer")
+
+  , abs = Math.abs;
+
+module.exports = function (value) {
+	if (!isInteger(value)) return false;
+	return abs(value) <= maxValue;
+};