docs: @Override
    @Beta
    protected boolean standardContainsKey(@Nullable Object key) {
      try {
        // any CCE will be caught
        @SuppressWarnings("unchecked")
        SortedMap<Object, V> self = (SortedMap<Object, V>) this;
        Object ceilingKey = self.tailMap(key).firstKey();
        return unsafeCompare(ceilingKey, key) == 0;
      } catch (ClassCastException e) {
        return false;
      } catch (NoSuchElementException e) {
        return false;
      } catch (NullPointerException e) {
        return false;
      }
    }