class Aws::Plugins::S3RequestSigner::BucketRegionErrorHandler

def wrong_sigv4_region?(resp)
  resp.context.http_response.status_code == 400 &&
  (
    resp.context.http_response.headers['x-amz-bucket-region'] ||
    resp.context.http_response.body_contents.match(/<Region>.+?<\/Region>/)
  )
end