# File lib/ruote/exp/flow_expression.rb, line 1002
    def apply_child(child_index, workitem, forget=false)

      msg = pre_apply_child(child_index, workitem, forget)

      persist_or_raise unless forget
        # no need to persist the parent (this) if the child is to be forgotten

      @context.storage.put_msg('apply', msg)
    end