code: function logEvent(model, event, state) {
    console.groupCollapsed('event:', event)
    console.log('new state:', state)
    if (model !== state.model) {
      console.log('model: from', model, 'to', state.model)
    } else {
      console.log('model (not changed):', model)
    }
    console.log('effect:', state.effect)
    console.groupEnd()
  }
docs: /* eslint no-console:0