class Google::Cloud::Env::ComputeMetadata

def internal_lookup path, query, open_timeout, request_timeout
  full_path = path ? "#{PATH_BASE}/#{path}" : ""
  http_response = connection.get full_path do |req|
    req.params = query if query
    req.headers = FLAVOR_HEADER
    req.options.timeout = request_timeout if request_timeout
    req.options.open_timeout = open_timeout if open_timeout
  end
  response = Response.new http_response.status, http_response.body, http_response.headers
  if path.nil?
    post_update_existence(response.status == 200 && response.google_flavor?, response.retrieval_monotonic_time)
  elsif response.google_flavor?
    post_update_existence true, response.retrieval_monotonic_time
  end
  lifetime = determine_data_lifetime path, response.body.strip
  LazyValue.expiring_value lifetime, response
rescue *TRANSIENT_EXCEPTIONS
  post_update_existence false
  raise MetadataServerNotResponding
end