def wfid

      l = [ @expressions, @errors, @stored_workitems ].find { |l| l.any? }

      l ? l.first.fei.wfid : nil
    end
def wfid

      l = [ @expressions, @errors, @stored_workitems ].find { |l| l.any? }

      l ? l.first.fei.wfid : nil
    end
Returns the unique identifier for this process instance.