code: void handle() throws IOException {
          if (null == handler) {
              println("Command not recognized: %s", command());
              return;
          }
          if (handler == Exit.INSTANCE) {
              handler.handle(this);
          }
          CommandLineParser parser = commandLine();
          boolean help = parser.getBoolean("-h", "--help");
          if (help) {
              Help.INSTANCE.showHelp(parser.command(), this);
          } else {
              try {
                  session.handler(handler);
                  handler.handle(this);
              } catch ($.Break b) {
                  throw b;
              } catch (Exception e) {
                  console.println("Error: " + e.getMessage());
              }
          }
      }
docs: Run handler and return `false` if it needs to exit the CLI or `true` otherwise