title: Drools 6 many agenda-groups declarations
body: <p>Can i only have one agenda-group declaration for the same rule in Drools 6?</p>
  
  <p>Can I put this?</p>
  
  <pre><code>rule "rule_x"
  agenda-group "group_x"
  agenda-group "group_y"
  when
  
  then
  end
  </code></pre>
  
  <p>I want to active a this rule when several groups are focused.</p>