added comment for abstract method

smgfreeman · smgfreeman · commit 6597e0aca7e3 · 2008-12-20T11:08:00.000Z
diff --git a/hamcrest-core/src/main/java/org/hamcrest/FeatureMatcher.java b/hamcrest-core/src/main/java/org/hamcrest/FeatureMatcher.java
@@ -28,6 +28,11 @@ public FeatureMatcher(Matcher<? super U> subMatcher, String featureDescription,
     this.featureName = featureName;
   }
   
+  /**
+   * Implement this to extract the interesting feature.
+   * @param actual the target object
+   * @return the feature to be matched
+   */
   protected abstract U featureValueOf(T actual);
 
   @Override
