Must take care of #at:put: by hand.

src/Znock/ZnockBase.class.st

@@ -18,6 +18,13 @@ ZnockBase class >> in: aZnock url: aZnUrl [
 		yourself
 ]
 
+{ #category : #public }
+ZnockBase >> at: keyString put: valueString [
+	self response.
+	^ builtClient response headers at: keyString put: valueString
+
+]
+
 { #category : #accessing }
 ZnockBase >> baseUrl [
 	^ baseUrl