void (@NotNull Buttons button, ShortcutSet @Nullable ... shortcutSets) { if (shortcutSets != null) { if (myCustomShortcuts == null) myCustomShortcuts = new EnumMap<>(Buttons.class); myCustomShortcuts.put(button, new CompositeShortcutSet(shortcutSets)); } else { if (myCustomShortcuts != null) { myCustomShortcuts.remove(button); if (myCustomShortcuts.isEmpty()) { myCustomShortcuts = null; } } } }