code: public RetryTemplateBuilder withListener(RetryListener listener) {
  		Assert.notNull(listener, "Listener should not be null");
  		listenersList().add(listener);
  		return this;
  	}
docs: Appends provided {@code listener} to {@link RetryTemplate}'s listener list.
  @param listener to be appended
  @return this
  @see RetryTemplate
  @see RetryListener