ClassUtils: add some explanation about performance

We may not _always_ need to include interfaces when recursively scanning
for annotated methods, but for now it does not seem worth worrying over.

Author: ctrueden

src/main/java/org/scijava/object/DefaultObjectService.java

@@ -31,7 +31,6 @@
 
 package org.scijava.object;
 
-
 import java.util.List;
 
 import org.scijava.event.EventHandler;

src/main/java/org/scijava/util/ClassUtils.java

@@ -311,6 +311,13 @@ public static <A extends Annotation> List<Method> getAnnotatedMethods(
 
 		// check supertypes for annotated methods first
 		getAnnotatedMethods(c.getSuperclass(), annotationClass, methods);
+		// NB: In some cases, we may not need to recursively scan interfaces.
+		// In particular, for the @EventHandler annotation, we only care about
+		// concrete methods, not interface method declarations. So we could have
+		// additional method signatures with a boolean toggle indicating whether
+		// to include interfaces in the recursive scan. But initial benchmarks
+		// suggest that the performance difference, even when creating a
+		// full-blown Context with a large classpath, is negligible.
 		for (final Class<?> iface : c.getInterfaces()) {
 			getAnnotatedMethods(iface, annotationClass, methods);
 		}