If some other package (like [google/cel-go](https://github.com/google/cel-go)) import antlr4 at the sametime it will cause conflict. ``` github.com/antlr/antlr4 github.com/antlr/antlr4/runtime/Go/antlr ``` maybe we should follow antlr4 [go.mod](https://github.com/antlr/antlr4/blob/master/runtime/Go/antlr/go.mod).
If some other package (like google/cel-go) import antlr4 at the sametime it will cause conflict.
maybe we should follow antlr4 go.mod.