chore: Adding mainFn helpers

lib/mainFn/LocalBinding.ts

@@ -0,0 +1,11 @@
+import { Origin } from "./Origin";
+
+export class LocalBinding {
+  constructor(readonly localAddress: string, readonly ipAddress: string) {}
+  createOrigins(protocol: string) {
+    return {
+      local: new Origin(protocol, this.localAddress),
+      ip: new Origin(protocol, this.ipAddress),
+    };
+  }
+}