protected void setExecutor(Executor executor) {
    m_executor = executor;
  }
Sets the {@link Executor} to use when dispatching {@link Notification}s.
This should only be used by unit tests to provide a mock executor.

@param executor
         the executor to use (not {@code null).
ambari-server/src/main/java/org/apache/ambari/server/state/services/AlertNoticeDispatchService.java