import Ember from 'ember';
              
              const { Service, get, assert } = Ember;
              
              /**
               * @class DataTableState
               * @extends Ember.Service
               */
              export default Service.extend({
                /**
                 * Serializes the current state of the table to be saved.
                 *
                 * @param {Table} table Object for the table to be serialized.
                 * @return {mixed} state Serialized state for the table.
                 */
                serialize(table) {
                  let visibleColumns = get(table, 'visibleColumns').mapBy('valuePath');
              
                  return {visibleColumns};
                },
              
                /**
                 * Deserializes a saved state and applies it's values to the table.
                 *
                 * @param {Table} table Table object where the state is to be applied.
                 * @param {mixed} state Saved state object the be applied.
                 */
                deserialize(table, state) {
                  get(table, 'columns').filter((item) => {
                    return state.visibleColumns.indexOf(item.get('valuePath')) === -1;
                  }).setEach('hidden', true);
                },
              
                /**
                 * Saves the current state of the table.
                 *
                 * @param {String} identifier Unique identifier for the table, used later to
                 * load the status.
                 * @param {mixed} state Table state as returned by `serialize()`.
                 * @param {Table} table Object for the table that should be saved.
                 */
                save(/* identifier, state, table */) {
                  assert('The save method must be implemented by a subclass');
                },
              
                /**
                 * Loads a previously saved state for a table.
                 *
                 * @param {String} identifier Unique identifier for the table to load status.
                 * @param {Table} table Object for the table that should be loaded.
                 * @return {mixed} Saved state for the specified table, that will be passed
                 *   to `deserialize()`.
                 */
                load(/* identifier, table */) {
                  assert('The load method must be implemented by a subclass');
                }
              });