Warning in example (data.preproc)

[NightlordTW]

v  checking files in 'vignettes' ... 
E  checking examples (1m 40s)
   Running examples in 'PrecMed-Ex.R' failed
   The error most likely occurred in:

   > base::assign(".ptime", proc.time(), pos = "CheckExEnv")
   > ### Name: cv
   > ### Title: Cross-validation of the conditional average treatment effect
   > ###   (CATE) score for count, survival or continuous outcomes
   > ### Aliases: cv
   > 
   > ### ** Examples
   > 
   > # Count outcome
   > output_cv <- cv(response = "count",
   +                 cate.model = y ~ age + female + previous_treatment +
   +                                      previous_cost + previous_number_relapses + offset(log(years)),
   +                 ps.model = trt ~ age + previous_treatment,
   +                 data = countExample,
   +                 higher.y = FALSE,
   +                 score.method = "poisson",
   +                 cv.n = 5,
   +                 plot.gbmperf = FALSE,
   +                 seed = 999)
   Warning in data.preproc(fun = "cv", cate.model = cate.model, ps.model = ps.model,  :
     Variable trt was recoded to 0/1 with drug0->0 and drug1->1.