fix #12200, cannot 'inc' CountTable by a negative value (#12208)
fix #12200, cannot 'inc' CountTable by a negative value (#12208)

* fix #12200, cannot 'inc' CountTable by a negative value

* use Positive

dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim