Prevent esc key to unselect selected node

By default esc key deselects current selection. Is there a way to prevent this? In my diagram I need to keep at least one node always selected. Thanks.

The ESC key invokes the CommandHandler.stopCommand.
Here’s how it’s implemented:

  public stopCommand() {
    const diagram = this.diagram;
    const tool = diagram.currentTool;
    if (tool instanceof ToolManager && diagram.allowSelect) {
      diagram.clearSelection();  // raises ChangingSelection/Finished
    if (tool !== null) {

Override that method not to call Diagram.clearSelection.