# File lib/ruote/engine/process_status.rb, line 202
    def to_h

      h = {}

      %w[
        wfid
        definition_name definition_revision
        original_tree current_tree
        variables tags
      ].each { |m| h[m] = self.send(m) }

      h['launched_time'] = launched_time.to_s

      # all_variables and all_tags ?

      h['root_expression'] = nil
      h['expressions'] = @expressions.collect { |e| e.fei.to_h }
      h['errors'] = @errors.collect { |e| e.to_h }

      h
    end