How do I initialize a Vec inside a Bundle literal in Chisel?

I'm trying to test a module which takes as input a UInt that follows the structure of this Bundle:

class Sample(n_attr: Int, n_classes: Int, n_depths: Int, info_bit: Int, tree_bit: Int) extends Bundle{
    val features = Vec(n_attr, FixedPoint(32.W,16.BP))
    val offset = UInt(info_bit.W)
    val shift = Bool()
    val search_for_root = Bool()
    val tree_to_exec = UInt(tree_bit.W)
    val scores = Vec(n_classes,FixedPoint(16.W,8.BP))
    val weights = Vec(n_depths, FixedPoint(16.W,8.BP))
    val dest = Bool()
    val last = Bool()
    val clock_cycles = UInt(32.W)
}

To avoid creating a binary string by hand (it would be 256 bits long) I'm trying to use Bundl literals like so:

c.wrapper_io.sample_in.TDATA.poke((new Sample(n_attr, n_classes, n_depths, info_bit, tree_bit)).Lit(
          _.features -> VecInit(0.F(8.BP), 0.F(8.BP), 0.F(8.BP), 0.F(8.BP), 0.F(8.BP)),
          _.offset -> 0.F(8.BP),
          _.shift -> false.B,
          _.search_for_root -> false.B,
          _.tree_to_exec -> 0.F(8.BP),
          _.scores -> VecInit(0.F(8.BP), 0.F(8.BP), 0.F(8.BP), 0.F(8.BP), 0.F(8.BP), 0.F(8.BP)),
          _.weights -> VecInit(0.F(8.BP), 0.F(8.BP), 0.F(8.BP), 0.F(8.BP), 0.F(8.BP), 0.F(8.BP)),
          _.dest -> false.B,
          _.last -> false.B,
          _.clock_cycles -> 0.U,
        ).litValue.U)

But when I try to compile I get the following error:

Error: Not in a UserModule. Likely cause: Missed Module() wrap, bare chisel API call, or attempting to construct hardware inside a BlackBox.

Is there a way to initialize Vecs inside Bundle literals? Thanks for the help!

Solution

I don't know how I missed it, but I found there is a way to do spcecifically this in the documentation. Here is how I fixed my code (there are a few other differences):

c.wrapper_io.sample_in.TDATA.poke((new Sample(n_attr, n_classes, n_depths, info_bit, tree_bit)).Lit(
          _.features -> Vec.Lit(0.0.F(32.W, 16.BP), 0.0.F(32.W, 16.BP), 0.0.F(32.W, 16.BP), 0.0.F(32.W, 16.BP), 0.0.F(32.W, 16.BP)),
          _.offset -> 0.U,
          _.shift -> false.B,
          _.search_for_root -> false.B,
          _.tree_to_exec -> 0.U,
          _.scores -> Vec.Lit(0.0.F(16.W, 8.BP), 0.0.F(16.W, 8.BP), 0.0.F(16.W, 8.BP), 0.0.F(16.W, 8.BP), 0.0.F(16.W, 8.BP), 0.0.F(16.W, 8.BP)),
          _.weights -> Vec.Lit(0.0.F(16.W, 8.BP)),
          _.dest -> false.B,
          _.last -> false.B,
          _.clock_cycles -> 0.U,
        ).litValue.U(best_width.W))

I also imported this:

import chisel3.experimental.VecLiterals._