Revision control
++ <?xml version="1.0" encoding="UTF-8"?>
++ <scxml xmlns="http://www.w3.org/2005/07/scxml" version="1.0" binding="early" name="HistoryState">
++ <state id="Working">
++ <state id="State1">
++ <onentry>
++ <send event="timeout" delay="1s"/>
++ </onentry>
++ </state>
++ <history type="shallow" id="HistoryState"/>
++ <transition type="external" event="timeout" target="State2"/>
++ </state>
++ <state id="State2"/>
++ </scxml>