message: [core] Add minor test case for sync cell multi sessions
diff: @@ -427,6 +427,23 @@ mod tests {
  })
  }
  + #[test]
  + fn multi_session_simulation() {
  + let mut cell1 = dummy_cell();
  + cell1.set(42);
  + assert_eq!(cell1.get(), Some(&42));
  + // Using same key as `cell1`
  + // -> overlapping access but different caches
  + // Cache has not yet been synced:
  + assert_eq!(dummy_cell().get(), None);
  + // Sync cache now!
  + cell1.flush();
  + // Using same key as `cell1`
  + // -> overlapping access but different caches
  + // Cache has been flushed before:
  + assert_eq!(dummy_cell().get(), Some(&42));
  + }
  +
  #[test]
  fn count_rw_get() {
  // Repetitions performed.
  