@RetainedLocalRef
      ImmutableCollection<? extends ListenableFuture<? extends InputT>> localFutures = futures;
      ImmutableCollection<? extends Future<? extends InputT>> localFuturesOrNull =
          collectsValues ? localFutures : null;
      Runnable listener = () -> decrementCountAndMaybeComplete(localFuturesOrNull);
      for (ListenableFuture<? extends InputT> future : localFutures) {
        if (future.isDone()) {

	}
}

// TestSignV4TrimAll - tests the logic of TrimAll() function
func TestSignV4TrimAll(t *testing.T) {
	testCases := []struct {
		// Input.
		inputStr string
		// Expected result.
		result string
	}{
		{"本語", "本語"},
		{" abc ", "abc"},
		{" a b ", "a b"},
		{"a b ", "a b"},
		{"a  b", "a b"},
		{"a   b", "a b"},
		{"   a   b  c   ", "a b c"},