@ApiStatus.Internal
  public static @NotNull @NlsSafe String toString(char mnemonic, boolean point) {
    StringBuilder sb = new StringBuilder().append(mnemonic);
    if (point) sb.append('.');
    return sb.toString(); //NON-NLS
  }
@ApiStatus.Internal
  public static @NotNull @NlsSafe String toString(char mnemonic, boolean point)