def do_pause(msg)

      return if h.state != nil

      h.state = 'paused'

      do_persist || return

      h.children.each { |i|
        @context.storage.put_msg('pause', 'fei' => i)
      } unless msg['breakpoint']
    end
def do_pause(msg)

      return if h.state != nil

      h.state = 'paused'

      do_persist || return

      h.children.each { |i|
        @context.storage.put_msg('pause', 'fei' => i)
      } unless msg['breakpoint']
    end
Expression received a "pause" message. Will put the expression in the
 "paused" state and then pass the message to the children.

 If the expression is in a non-nil state (failed, timed_out, ...), the
 message will be ignored.