Improve HTTP headers option

option/types.go

@@ -1,6 +1,7 @@
 package option
 
 import (
+	"net/http"
 	"net/netip"
 	"strings"
 	"time"
@@ -235,3 +236,15 @@ func DNSQueryTypeToString(queryType uint16) string {
 	}
 	return F.ToString(queryType)
 }
+
+type HTTPHeader map[string]Listable[string]
+
+func (h HTTPHeader) Build() http.Header {
+	header := make(http.Header)
+	for name, values := range h {
+		for _, value := range values {
+			header.Add(name, value)
+		}
+	}
+	return header
+}