def handle_on_error(msg, err)

      r = trigger_callback(:on_error, msg, err)

      if r
        reply_to_parent(msg['workitem'])
        true # yes, we've dealt with the error.
      else
        super(msg, err)
      end
    end
def handle_on_error(msg, err)

      r = trigger_callback(:on_error, msg, err)

      if r
        reply_to_parent(msg['workitem'])
        true # yes, we've dealt with the error.
      else
        super(msg, err)
      end
    end
Overrides FlowExpression#handle_on_error. Attempts to call a
 potential #on_error method in the participant implementation.

 If that method exists and returns something true-ish, will not call
 the super #handle_on_error, it will directly reply to the parent.