How to use the quasar.LocalStorage.set function in quasar

updateStats: debounce(state => {
      state.content = convertHtmlToTxt(state.contentHTML)
      state.sentences = state.content
        .replace(/(\.+|:|;|\?|!)/g, '$1\n')
        .split(/\n+\s*/)
        .filter(n => n)
      state.words = state.content.split(/\s+/).filter(n => n)
      if (state.words) {
        LocalStorage.set(CONTENT_BACKUP_KEY, state.contentHTML)
      } else {
        LocalStorage.remove(CONTENT_BACKUP_KEY)
      }
    }, 100 /* Execute at most once every 100ms */)
  },

updateContentAndStats () {
      this.content = this.convertHtmlToTxt(this.contentHTML)
      // Store backup content (only if there is valid text)
      if (this.content && this.content.length > 0) {
        LocalStorage.set(CONTENT_BACKUP_KEY, this.contentHTML)
      }
      else {
        LocalStorage.remove(CONTENT_BACKUP_KEY)
      }
      this.sentences = this.content
        .replace(/(\.+|:|;|\?|!)/g, '$1\n')
        .split(/\n+\s*/)
        .filter(n => n)
      this.words = this.content
        .split(/\s+/)
        .filter(n => n)
    },
    processEditOperation (operation) {

.then((response) => {
        // Store refreshed token
        axios.defaults.headers.common['Authorization'] = 'Bearer ' + response.data.token
        LocalStorage.set('id_token', response.data.token)
        Toast.create.positive('You have successfully logged in.')
        that.getAuthUser()
      }, () => {
        Toast.create.negative('Something went wrong with your login!!')

handler (data) {
              if (data.name.length > 0) {
                if (data.name.length <= 25) {
                  var list = {
                    name: data.name,
                    tasks: []
                  }
                  self.$root.lists.unshift(list)
                  Toast.create.positive('Your list is was created!')
                  LocalStorage.set('lists', self.$root.lists)
                }
                else {
                  Toast.create.negative('Please use 25 characters or less.')
                }
              }
              else {
                Toast.create.negative('Your list could not be created! Please fill in all fields.')
              }
            }
          }

updateRoot () {
      var self = this
      self.$root.lists[self.id] = self.list
      LocalStorage.set('lists', self.$root.lists)
    },
    listActions () {

updateSettings (state, settings) {
      state.settings = Object.assign({}, state.settings, settings)
      LocalStorage.set(SETTINGS_KEY, state.settings)
      updateAddressbarColor(state.settings.darkMode)
    },

toggle (key) {
      if (LocalStorage.has(key)) {
        LocalStorage.remove(key)
      }
      else {
        LocalStorage.set(key, `${key}-value`)
      }
      this.update()
    },
    clear () {

created () {
    if (!LocalStorage.has('lists')) {
      LocalStorage.set('lists', [])
    }
    this.$root.lists = LocalStorage.get.item('lists')
  },
  methods: {

break
    case 'WIPE_CHOSEN':
      state.chosen = []
      LocalStorage.remove('chosen')
      break
    case 'CHANGE_CHOSEN':
      if (action.data.want) {
        state.chosen.push(action.data.id)
      }
      else {
        let index = state.chosen.indexOf(action.data.id)
        if (index >= 0) state.chosen.splice(index, 1)
      }

      if (state.chosen.length) {
        LocalStorage.set('chosen', state.chosen.join(','))
      }
      else {
        LocalStorage.remove('chosen')
      }
      break
    case 'SEARCH_CHANGED':
      state.page = 1
      break
  }
}