set abstract method

void set(String name, Object value)

Sets a header. The header named name will have all its values cleared before the value value is added as its value.

Source

void set(String name, Object value);

© 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/set.html