class Aws::S3::Plugins::S3Signer::BucketRegionErrorHandler

def custom_endpoint?(resp)
  region = resp.context.config.region
  partition = Aws::Endpoints::Matchers.aws_partition(region)
  endpoint = resp.context.http_request.endpoint
  !endpoint.hostname.include?(partition['dnsSuffix']) &&
    !endpoint.hostname.include?(partition['dualStackDnsSuffix'])
end