Adapts a custom `torch` model trained in R for use with CounterfactualExplantions.jl.

adapt_torch_model.jl

using Flux
using CounterfactualExplanations, CounterfactualExplanations.Models
import CounterfactualExplanations.Models: logits, probs # import functions in order to extend

# Step 1)
struct TorchNetwork <: Models.AbstractFittedModel
    nn::Any
end

# Step 2)
function logits(M::TorchNetwork, X::AbstractArray)
  nn = M.nn
  y = rcopy(R"as_array($nn(torch_tensor(t($X))))")
  y = isa(y, AbstractArray) ? y : [y]
  return y'
end
function probs(M::TorchNetwork, X::AbstractArray)
  return σ.(logits(M, X))
end
M = TorchNetwork(R"model")