`$params` not working without ka

[mattfidler]

library(rxode2)
#> Warning: package 'rxode2' was built under R version 4.3.3
#> rxode2 2.1.3 using 4 threads (see ?getRxThreads)
#>   no cache: create with `rxCreateCache()`

mod <- function() {
  ini({
    cl <- 0.1
    vc <- 4
    err.sd <- 0.1
  })
  model({
    Cc <- linCmt(cl, vc)
    Cc ~ add(err.sd)
  })
}

mod <- mod()

mod$params
#> Error in if (.mv$extramt == 1L) {: argument is of length zero

^{Created on 2024-06-23 with reprex v2.1.0}