Coding style.

Moved the Result class into tools, which simplifies worker.py and makes the
circular import problem go away.

tools_test.py

@@ -188,5 +188,28 @@ class ToolsTestCase(unittest.TestCase):
         self._test_tool(tools.php5_syntax, [("root.php", tools.Status.ok)])
 
 
+class LruCacheWithEvictionTestCase(unittest.TestCase):
+
+    def _assert_cache(self, func, hits, misses, current_size):
+        cache_info = func.cache_info()
+        self.assertEqual(cache_info.hits, hits)
+        self.assertEqual(cache_info.misses, misses)
+        self.assertEqual(cache_info.currsize, current_size)
+
+    def test_lru_cache_with_eviction(self):
+        @tools.lru_cache_with_eviction()
+        def a(foo):
+            return foo
+        self._assert_cache(a, 0, 0, 0)
+        self.assertEqual(a(1), 1)
+        self._assert_cache(a, 0, 1, 1)
+        a(1)
+        self._assert_cache(a, 1, 1, 1)
+        a.evict(1)
+        self._assert_cache(a, 1, 1, 1)
+        a(1)
+        self._assert_cache(a, 1, 2, 2)
+
+
 if __name__ == "__main__":
     golden.main()