Character vector. Destination directory for checkpoints. Leave
NULL
to allow RBERT to automatically choose a directory. The path is
determined from the dir
parameter if supplied, followed by the
`RBERT.dir` option (set using set_BERT_dir), followed by an "RBERT"
folder in the user cache directory (determined using
user_cache_dir
). If you provide a dir
, the
`RBERT.dir` option will be updated to that location. Note that the
checkpoint will create a subdirectory inside this dir
.