Bump to v4.0.0.

internal/Hash.js

@@ -0,0 +1,17 @@
+import nativeCreate from './nativeCreate';
+
+/** Used for built-in method references. */
+var objectProto = Object.prototype;
+
+/**
+ * Creates an hash object.
+ *
+ * @private
+ * @returns {Object} Returns the new hash object.
+ */
+function Hash() {}
+
+// Avoid inheriting from `Object.prototype` when possible.
+Hash.prototype = nativeCreate ? nativeCreate(null) : objectProto;
+
+export default Hash;