handle last peer error case [CI SKIP]

wg-event-gen/src/model.rs

@@ -194,6 +194,10 @@ impl PeerBuilder {
         self.validate().is_ok()
     }
 
+    pub fn has_key(&self) -> bool {
+        self.key.is_some()
+    }
+
     pub fn add_allowed_ip(&mut self, ip: (IpAddr, u8)) {
         if let Some(ref mut ips) = &mut self.allowed_ips {
             ips.push(ip);