android support! thanks to TachiWeb devs.

AndroidCompat/src/main/java/com/f2prateek/rx/preferences/Preconditions.java

@@ -0,0 +1,30 @@
+/*
+Copyright 2014 Prateek Srivastava
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+This file may have been modified after being copied from it's original source.
+ */
+package com.f2prateek.rx.preferences;
+
+final class Preconditions {
+  static void checkNotNull(Object o, String message) {
+    if (o == null) {
+      throw new NullPointerException(message);
+    }
+  }
+
+  private Preconditions() {
+    throw new AssertionError("No instances");
+  }
+}