# File lib/ruote/exp/flow_expression.rb, line 207
    def root(stubborn=false)

      previous = nil
      current = @h

      exps = @context.storage.find_expressions(
        @h['fei']['wfid']
      ).each_with_object({}) { |exp, h|
        h[exp['fei']] = exp
      }

      while current && current['parent_id']
        previous = current
        current = exps[current['parent_id']]
      end

      current ||= previous unless stubborn

      current ? Ruote::Exp::FlowExpression.from_h(@context, current) : nil
    end