message: [core] make TestEnv fn emmited_events return a double ended iterator
diff: @@ -295,7 +295,7 @@ impl TestEnvData {
  }
  /// Returns an iterator over all emitted events.
  - pub fn emitted_events(&self) -> impl Iterator<Item = &[u8]> {
  + pub fn emitted_events(&self) -> impl DoubleEndedIterator<Item = &[u8]> {
  self.events
  .iter()
  .map(|event_data| event_data.data_as_bytes())
  @@ -460,7 +460,7 @@ impl<T> TestEnv<T> where T: EnvTypes {
  );
  /// Returns an iterator over all emitted events.
  - pub fn emitted_events() -> impl Iterator<Item = Vec<u8>> {
  + pub fn emitted_events() -> impl DoubleEndedIterator<Item = Vec<u8>> {
  TEST_ENV_DATA.with(|test_env| {
  test_env
  .borrow()
  