package webextension_polyfill.webrequest;
/**
Fired when HTTP response headers of a request have been received.
**/
typedef OnHeadersReceivedEvent = {
/**
Registers an event listener callback to an event.
**/
function addListener(callback:(details:OnHeadersReceivedDetailsType) -> ts.AnyOf3>, filter:RequestFilter, ?extraInfoSpec:Array):Void;
/**
Deregisters an event listener callback from an event.
**/
function removeListener(callback:(details:OnHeadersReceivedDetailsType) -> ts.AnyOf3>):Void;
function hasListener(callback:(details:OnHeadersReceivedDetailsType) -> ts.AnyOf3>):Bool;
function hasListeners():Bool;
};