def stash_get(workitem_or_fei, key=nil)

      stash = fetch_flow_expression(workitem_or_fei).h['stash'] rescue nil
      stash ||= {}

      key ? stash[key] : stash
    end
def stash_get(workitem_or_fei, key=nil)

      stash = fetch_flow_expression(workitem_or_fei).h['stash'] rescue nil
      stash ||= {}

      key ? stash[key] : stash
    end
Fetches back a stashed value.

   get(fei, 'colour')
     # => 'blue'

 To return the whole stash

   get(fei)
     # => { 'colour' => 'blue' }

 put & get are useful for a participant that needs to communicate
 between its consume and its cancel.