code: function(buckets) {
      var bucketRegionCache = this.bucketRegionCache;
      if (!buckets) {
        buckets = Object.keys(bucketRegionCache);
      } else if (typeof buckets === 'string') {
        buckets = [buckets];
      }
      for (var i = 0; i < buckets.length; i++) {
        delete bucketRegionCache[buckets[i]];
      }
      return bucketRegionCache;
     }
docs: Clears bucket region cache.
  
  @api private