dart:io

clear abstract method

void clear()

Remove all headers. Some headers have system supplied values and for these the system supplied values will still be added to the collection of values for the header.

Source 

void clear();

© 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/clear.html