docs: @Nullable
    private static Modifier getTokModifierKind(ErrorProneToken tok) {
      switch (tok.kind()) {
        case PUBLIC:
          return Modifier.PUBLIC;
        case PROTECTED:
          return Modifier.PROTECTED;
        case PRIVATE:
          return Modifier.PRIVATE;
        case ABSTRACT:
          return Modifier.ABSTRACT;
        case STATIC:
          return Modifier.STATIC;
        case FINAL:
          return Modifier.FINAL;
        case TRANSIENT:
          return Modifier.TRANSIENT;
        case VOLATILE:
          return Modifier.VOLATILE;
        case SYNCHRONIZED:
          return Modifier.SYNCHRONIZED;
        case NATIVE:
          return Modifier.NATIVE;
        case STRICTFP:
          return Modifier.STRICTFP;
        case DEFAULT:
          return Modifier.DEFAULT;
        default:
          return null;
      }
    }