java.lang.NullPointerException at the.bytecode.club.bytecodeviewer.CommandLineInput.accept(CommandLineInput.java:335)

```
$ java -jar .../Bytecode-Viewer-2.9.19.jar -decompiler FernFlower -i src/lang/Lang.class -o Lang.java -t lang.Lang

https://the.bytecode.club - Created by @Konloch - Bytecode Viewer 2.9.19, Fat-Jar: true
Start up took 6 seconds
Decompiling /home/zaoqi/src/the-language/core/pure/java/src/lang/Lang.class with FernFlower
java.lang.NullPointerException
at the.bytecode.club.bytecodeviewer.CommandLineInput.accept(CommandLineInput.java:335)
at the.bytecode.club.bytecodeviewer.CommandLineInput.executeCommandLine(CommandLineInput.java:239)
at the.bytecode.club.bytecodeviewer.BytecodeViewer.main(BytecodeViewer.java:558)
java.lang.NullPointerException
at the.bytecode.club.bytecodeviewer.CommandLineInput.accept(CommandLineInput.java:340)
at the.bytecode.club.bytecodeviewer.CommandLineInput.executeCommandLine(CommandLineInput.java:239)
at the.bytecode.club.bytecodeviewer.BytecodeViewer.main(BytecodeViewer.java:558)
```

Start with CommandLineInput.java at lines 335 and 340, then follow executeCommandLine and BytecodeViewer.main from the stack trace. Re-run the reported FernFlower command against src/lang/Lang.class and verify that the command completes without the reported NullPointerExceptions.

Written by the indexing model from the issue text.