Add API 31 sources

Test: None
Change-Id: Ie45894f7a232b2a15e2439b2527ca1813f334cc5

android/test/SimpleCache.java

diff --git a/android/test/SimpleCache.java b/android/test/SimpleCache.java
new file mode 100644
index 0000000..46143e4
--- /dev/null
+++ b/android/test/SimpleCache.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * 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.
+ */
+
+package android.test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Deprecated
+abstract class SimpleCache<K, V> {
+    private Map<K, V> map = new HashMap<K, V>();
+
+    protected abstract V load(K key);
+
+    final V get(K key) {
+        if (map.containsKey(key)) {
+            return map.get(key);
+        }
+        V value = load(key);
+        map.put(key, value);
+        return value;
+    }
+}