Added some comments.

src/main/java/org/cojen/dirmi/core/Item.java

@@ -23,6 +23,10 @@
  * Base class for objects which are associated with an identifier. They can be stored within a
  * single ItemMap instance.
  *
+ * <p>This class is subclassed by Stub and so it must not declare any new public instance
+ * methods because they can conflict with user-specified remote methods which have the same
+ * signature.
+ *
  * @author Brian S O'Neill
  * @see ItemMap
  * @see IdGenerator

src/main/java/org/cojen/dirmi/core/Stub.java

@@ -23,7 +23,8 @@
 import org.cojen.dirmi.Remote;
 
 /**
- * Base class for remote stubs.
+ * Base class for remote stubs. It must not declare any new public instance methods because
+ * they can conflict with user-specified remote methods which have the same signature.
  *
  * @author Brian S O'Neill
  */
@@ -69,6 +70,9 @@ public Stub(long id, StubSupport support, MethodIdWriter miw) {
     /**
      * Returns true if this stub is restorable following a disconnect.
      *
+     * Note: This method must not be public or else it can conflict with a user-specified
+     * remote method which has the same signature.
+     *
      * @see #setRootOrigin
      */
     final boolean isRestorable() {

src/main/java/org/cojen/dirmi/core/StubMaker.java

@@ -506,7 +506,6 @@ private void writeParams(MethodMaker mm, Variable pipeVar,
             writeName = "writeSyntheticMethodId";
         }
 
-
         mm.field("miw").getAcquire().invoke(writeName, pipeVar, methodId, method.name());
 
         if (ptypes.length <= 0) {