Keymap getMutableKeymap(Keymap keymap) {
    KeymapScheme scheme = find(keymap);
    if (scheme == null) return null;
    if (scheme.isMutable()) return scheme.getMutable();

    String name = KeyMapBundle.message("new.keymap.name", keymap.getPresentableName());
    for (int i = 1; containsScheme(name, false); i++) {
      name = KeyMapBundle.message("new.indexed.keymap.name", keymap.getPresentableName(), i);
    }
    return copyScheme(scheme, name).getMutable();
  }
Keymap getMutableKeymap(Keymap keymap)