Class SnapshotRecordArray

import MyCustomAdapter from './custom-adapter';

export default class PostAdapter extends MyCustomAdapter {
  findAll(store, type, sinceToken, snapshotRecordArray) {
    if (snapshotRecordArray.adapterOptions.subscribe) {
      // ...
    }
    // ...
  }
}

import Adapter from '@ember-data/adapter';

export default class ApplicationAdapter extends Adapter {
  findAll(store, type, snapshotRecordArray) {
    let url = `/${type.modelName}?include=${encodeURIComponent(snapshotRecordArray.include)}`;

    return fetch(url).then((response) => response.json())
  }
}

import JSONAPIAdapter from '@ember-data/adapter/json-api';

export default class PostAdapter extends JSONAPIAdapter {
  shouldReloadAll(store, snapshotRecordArray) {
    return !snapshotRecordArray.length;
  }
});