Replace RelayMap::extend() member fn with RelayMap::join

Signed-off-by: Matthias Beyer <[email protected]>

Author: matthiasbeyer

iroh-relay/src/relay_map.rs

@@ -112,11 +112,14 @@ impl RelayMap {
         self.relays.write().expect("poisoned").remove(url)
     }
 
-    /// Extends this `RelayMap` with another one.
-    pub fn extend(&self, other: &RelayMap) {
-        let mut a = self.relays.write().expect("poisoned");
-        let b = other.relays.read().expect("poisoned");
-        a.extend(b.iter().map(|(a, b)| (a.clone(), b.clone())));
+    /// Joins this `RelayMap` with another one into a new one
+    pub fn join(self, other: RelayMap) -> RelayMap {
+        {
+            let mut a = self.relays.write().expect("poisoned");
+            let b = other.relays.read().expect("poisoned");
+            a.extend(b.iter().map(|(a, b)| (a.clone(), b.clone())));
+        }
+        self
     }
 }