Bump to v4.1.0.

_SetCache.js

@@ -0,0 +1,24 @@
+define(['./_MapCache', './_cachePush'], function(MapCache, cachePush) {
+
+  /**
+   *
+   * Creates a set cache object to store unique values.
+   *
+   * @private
+   * @param {Array} [values] The values to cache.
+   */
+  function SetCache(values) {
+    var index = -1,
+        length = values ? values.length : 0;
+
+    this.__data__ = new MapCache;
+    while (++index < length) {
+      this.push(values[index]);
+    }
+  }
+
+  // Add functions to the `SetCache`.
+  SetCache.prototype.push = cachePush;
+
+  return SetCache;
+});