fix: address some comments

Signed-off-by: Zhangjian He <[email protected]>

stream/distributedlog/core/src/test/java/org/apache/distributedlog/feature/TestDynamicConfigurationFeatureProvider.java

@@ -82,7 +82,42 @@ public void testLoadFeaturesFromBase() throws Exception {
 
     @FlakyTest("https://issues.apache.org/jira/browse/DL-40")
     public void testLoadFeaturesFromOverlay() throws Exception {
-        Assertions.fail("xxx");
+        PropertiesWriter writer = new PropertiesWriter();
+        writer.setProperty("feature_1", "10000");
+        writer.setProperty("feature_2", "5000");
+        writer.save();
+
+        PropertiesWriter overlayWriter = new PropertiesWriter();
+        overlayWriter.setProperty("feature_2", "6000");
+        overlayWriter.setProperty("feature_4", "6000");
+        overlayWriter.save();
+
+        DistributedLogConfiguration conf = new DistributedLogConfiguration()
+                .setDynamicConfigReloadIntervalSec(Integer.MAX_VALUE)
+                .setFileFeatureProviderBaseConfigPath(writer.getFile().toURI().toURL().getPath())
+                .setFileFeatureProviderOverlayConfigPath(overlayWriter.getFile().toURI().toURL().getPath());
+        DynamicConfigurationFeatureProvider provider =
+                new DynamicConfigurationFeatureProvider("", conf, NullStatsLogger.INSTANCE);
+        provider.start();
+        ensureConfigReloaded();
+
+        Feature feature1 = provider.getFeature("feature_1");
+        assertTrue(feature1.isAvailable());
+        assertEquals(10000, feature1.availability());
+        Feature feature2 = provider.getFeature("feature_2");
+        assertTrue(feature2.isAvailable());
+        assertEquals(6000, feature2.availability());
+        Feature feature3 = provider.getFeature("feature_3");
+        assertFalse(feature3.isAvailable());
+        assertEquals(0, feature3.availability());
+        Feature feature4 = provider.getFeature("feature_4");
+        assertTrue(feature4.isAvailable());
+        assertEquals(6000, feature4.availability());
+        Feature feature5 = provider.getFeature("unknown_feature");
+        assertFalse(feature5.isAvailable());
+        assertEquals(0, feature5.availability());
+
+        provider.stop();
     }
 
     @Test