fix(Utils): use 'match.fun' instead of 'get' to get the body of a modelling function

Refs #119
3 jobs for 119-fix-broken-package-reverse-dependency in 9 minutes and 16 seconds (queued for 38 minutes and 36 seconds)
Status Job ID Name Coverage
  Check
passed #168347
check_as_cran_patched

00:02:41

passed #168346
check_not_cran_patched

00:05:25

 
  Regression
passed #168348
regression_patched

00:01:08