set (index, value) {
    if (this.context) {
      this.context.setListIndex(this.path, index, value)
    } else if (!this[OBJECT_ID]) {
      this.elems[index].value = value
    } else {
      throw new TypeError('Automerge.Text object cannot be modified outside of a change block')
    }
    return this
  }
Updates the list item at position `index` to a new value `value`.