update(extent, value) {
    const item = this.items_[getUid(value)];
    const bbox = [item.minX, item.minY, item.maxX, item.maxY];
    if (!equals(bbox, extent)) {
      this.remove(value);
      this.insert(extent, value);
    }
  }
Update the extent of a value in the RBush.
@param {import("../extent.js").Extent} extent Extent.
@param {T} value Value.