code: def _get_bucket_region(self, bucket_name):
          
  
          # Region set in constructor, return right here.
          if self._region:
              return self._region
  
          # get bucket location for Amazon S3.
          region = 'us-east-1'  # default to US standard.
          if bucket_name in self._region_map:
              region = self._region_map[bucket_name]
          else:
              region = self._get_bucket_location(bucket_name)
              self._region_map[bucket_name] = region
  
          # Success.
          return region
docs: Get region based on the bucket name.
  
          :param bucket_name: Bucket name for which region will be fetched.
          :return: Region of bucket name.