@SuppressWarnings("unused")
  // used in debugger renderer
  private Map.Entry<K,V>[] childrenArray() {
    //noinspection unchecked
    return myMap.entrySet().stream()
      .map(entry -> {
        Object val = SoftReference.deref(entry.getValue());
        return val != null ? new AbstractMap.SimpleImmutableEntry<>(entry.getKey(), val) : null;
      })
      .filter(Objects::nonNull)
      .toArray(Entry[]::new);
  }
@SuppressWarnings("unused")
  // used in debugger renderer
  private Map.Entry<K,V>[] childrenArray()