Modularize master branch.

_Hash.js

@@ -0,0 +1,32 @@
+import hashClear from './_hashClear.js';
+import hashDelete from './_hashDelete.js';
+import hashGet from './_hashGet.js';
+import hashHas from './_hashHas.js';
+import hashSet from './_hashSet.js';
+
+/**
+ * Creates a hash object.
+ *
+ * @private
+ * @constructor
+ * @param {Array} [entries] The key-value pairs to cache.
+ */
+function Hash(entries) {
+  var index = -1,
+      length = entries == null ? 0 : entries.length;
+
+  this.clear();
+  while (++index < length) {
+    var entry = entries[index];
+    this.set(entry[0], entry[1]);
+  }
+}
+
+// Add methods to `Hash`.
+Hash.prototype.clear = hashClear;
+Hash.prototype['delete'] = hashDelete;
+Hash.prototype.get = hashGet;
+Hash.prototype.has = hashHas;
+Hash.prototype.set = hashSet;
+
+export default Hash;