message: Missing comments.
diff: @@ -4,11 +4,19 @@ import { D2Item } from '../inventory/item-types';
  import { getPowerMods } from '../inventory/store/d2-item-factory.service';
  import { DtrD2BasicItem, D2ItemFetchRequest } from '../item-review/d2-dtr-api-types';
  +/**
  + * Lookup keys for review data in the cache.
  + * Reference ID comes from the underlying item's hash ID.
  + * Available perks is a collection of the item instance's available plug hash IDs.
  + */
  export interface D2ReviewKey {
  referenceId: number;
  availablePerks?: number[];
  }
  +/**
  + * Translate a D2 item into its review key.
  + */
  export function getReviewKey(
  item?: D2Item | DestinyVendorSaleItemComponent,
  itemHash?: number
  @@ -29,6 +37,10 @@ export function getReviewKey(
  }
  }
  +/**
  + * Translate a collection of available perks (plug hash IDs) into a string.
  + * Useful in reducers and other places where arrays aren't super useful.
  + */
  export function getD2Roll(availablePerks?: number[]): string {
  return availablePerks && availablePerks.length > 0 ? availablePerks.join(',') : 'fixed';
  }
  