$slice does not support AggregationExpression for offset and itemCount

[Saljack]

I try to write aggregation with $slice and split an array and use another expression for itemCount. But current ArrayOperators.Slice supports only int for offset and itemCount. These values can be also expression see https://www.mongodb.com/docs/manual/reference/operator/aggregation/slice/
For example I would like to slice an array myArray and remove the last item from this array:

"arrayWithoutLastItem": {
  "$slice": [
    "$myArray",
      { "$subtract":  [ {"$size": "$myArray"}, 1]}
   ]
}

I would like to write it like this:

ArrayOperators.Slice.sliceArrayOf("myArray")
    .itemCount(
      Subtract.valueOf(
         ArrayOperators.Size.lengthOfArray("myArray")
      ).subtract(1)
   )

[christophstrobl]

Thanks for the heads up @Saljack! Yes, that seems to be missing in Slice.