<?xml version="1.0"?>
<block>
  <name>Message Sink</name>
  <key>gsm_message_sink</key>
  <import>import grgsm</import>
  <make>grgsm.message_sink()</make>

  <sink>
    <name>in</name>
    <type>message</type>
  </sink>
  
  <doc>
This block is a message sink for testing purposes.

The data can be retrieved using function get_messages()

  </doc>
</block>