Постоянная RESPONSE_HEADERS
dynamic RESPONSE_HEADERS = const [ACCEPT_RANGES, AGE, ETAG, LOCATION, PROXY_AUTHENTICATE, RETRY_AFTER, SERVER, VARY, WWW_AUTHENTICATE]
© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dartlang.org/stable/1.24.3/dart-io/HttpHeaders/RESPONSE_HEADERS-constant.html
