constructor({
    cellCount,
    cellSizeGetter,
    estimatedCellSize,
  }: CellSizeAndPositionManagerParams) {
    this._cellSizeGetter = cellSizeGetter;
    this._cellCount = cellCount;
    this._estimatedCellSize = estimatedCellSize;
  }
Just-in-time calculates and caches size and position information for a collection of cells.