header.go
func (h *ResponseHeader) Set(key, value string) {
	initHeaderKV(&h.bufKV, key, value, h.disableNormalizing)
	h.SetCanonical(h.bufKV.key, h.bufKV.value)
}
func (h *ResponseHeader) Set(key, value string) {
	initHeaderKV(&h.bufKV, key, value, h.disableNormalizing)
	h.SetCanonical(h.bufKV.key, h.bufKV.value)
}
func ( h * ResponseHeader ) Set ( key , value string ) { initHeaderKV ( & h . bufKV , key , value , h . disableNormalizing ) h . SetCanonical ( h . bufKV . key , h . bufKV . value ) }
// Set sets the given 'key: value' header.
//
// Use Add for setting multiple header values under the same key.
Set sets the given key : value header . Use Add for setting multiple header values under the same key .