@SuppressWarnings("unchecked")
  @Override
  public V remove(final Object key) {
    final V oldValue = delegate.remove(key);
    if (oldValue != null) {
      undoLog.add(new UndoEntry<>((K) key, oldValue));
    }
    return oldValue;
  }
Has the map been changed

@return true if there are any undo entries in the log
evm/src/main/java/org/hyperledger/besu/collections/undo/UndoMap.java