Enumerates the headers, applying the function f
to each header. The header name passed in name
will be all lower case.
void forEach(void f(String name, List<String> values));
© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.5.0/dart-io/HttpHeaders/forEach.html