block8.js

class ViewabilityHelper {
  _config: ViewabilityConfig;
  _hasInteracted: boolean = false;
  /* A set of `timeoutID`, used for memory management */
  _timers: Set<number> = new Set();
  // Indexs of the viewable items
  _viewableIndices: Array<number> = [];
  // A map for viewable items
  _viewableItems: Map<string, ViewToken> = new Map();
}