private void commandHelp(CliCommand command) {
    String parameters = command.getParameters();
    if (CliUtil.isNullOrEmpty(parameters)) {
      printHelpMessage();
      return;
    }

    parameters = parameters.trim().toUpperCase();
    for (CliCommandType cmdType : CliCommandType.values()) {
      String cmdText = cmdType.getCommandName();
      if (cmdText.equals(parameters)) {
        writer.println(cmdType.getUsage());
        writer.flush();
        return;
      }
    }

    writer.print("Unknown command: ");
    writer.println(parameters);
    writer.flush();
  }
Handles the given command
@param command input {@link CliCommand} to handle
@return false if command is to quit, or fatal error happened that Shell should not continue running. True o.w.
@throws CommandHandlerException if unrecoverable error happened while handling the input {@link CliCommand}
samza-sql-shell/src/main/java/org/apache/samza/sql/client/impl/CliCommandHandler.java