Add test and improve example

.github/workflows/loom.yml

@@ -14,6 +14,7 @@ on:
       - 'asynchronix/src/ports/output/broadcaster/**'
       - 'asynchronix/src/ports/source/broadcaster.rs'
       - 'asynchronix/src/ports/source/broadcaster/**'
+      - 'asynchronix/src/util/cached_rw_lock.rs'
       - 'asynchronix/src/util/slot.rs'
       - 'asynchronix/src/util/sync_cell.rs'
 
@@ -31,4 +32,4 @@ jobs:
       - name: Run cargo test (Loom)
         run: cargo test --tests --release
         env:
-          RUSTFLAGS: --cfg asynchronix_loom
+          RUSTFLAGS: --cfg asynchronix_loom