CDTKF Slice Function

I am having an issue while using slice function after upgrading from 0.15.3 to 0.16.1.

Here is my typescript code:

    const regionEast = new TerraformVariable(this, "regionEast", {
      type: "string",
      description: "CIDR Pool for US-EAST-2 Region",

    const range = Array.from(Array(16).keys()).map(() => 4);

    const cidrs = Fn.cidrsubnets(regionEast.value, range);

    const iterator = TerraformIterator.fromList(
      Fn.slice(cidrs, 0, Fn.sum([Fn.lengthOf(cidrs), -1]))

This is the error I am getting: