code: public ReturnValue invoke(final String commandName, final String[] argsAry) {
          if ("_NRPE_CHECK".equals(commandName)) {
              return new ReturnValue(Status.OK, JNRPELIB.VERSION);
          }
  
          CommandDefinition cd = commandRepository.getCommand(commandName);
  
          if (cd == null) {
              return new ReturnValue(Status.UNKNOWN, "Bad command");
          }
  
          return invoke(cd, argsAry);
      }
docs: This method executes built in commands or builds a CommandDefinition to.
  execute external commands (plugins). The methods also expands the $ARG?$
  macros.
  
  @param commandName
  The name of the command, as configured in the server
  configuration XML
  @param argsAry
  The arguments to pass to the command as configured in the
  server configuration XML (with the $ARG?$ macros)
  @return The result of the command