Public void UnRegCmd(String command_name) {
  try {
    HashMap<String, Command> known_commands = (HashMap<String, Command>) this.getPrivateField((CommandMap) this.getPrivateField(this.pm, "commandMap"), "knownCommands");
     for (String alias : this.getCommand(command_name).getAliases()) {
       known_commands.remove(command_name);
     }
   known_commands.remove(command_name);
   } catch (SecurityException | NoSuchFieldException | IllegalArgumentException | IllegalAccessException ex) {
     this.utils.writeWatchdogExceptionLog(this, this.getClass(), ex);
   }
}

private Object getPrivateField(Object object, String field) throws
        SecurityException,
        NoSuchFieldException,
        IllegalArgumentException,
        IllegalAccessException {
    Field objectField = object.getClass().getDeclaredField(field);
    objectField.setAccessible(true);
    return objectField.get(object);
}