- if moving a file from a group, need to remove the entire group
  - Special test for when dest is a non-existent directory

dirname. Make it abs

called() to get the function.

check data shape, and raise if bad.

files. Adjustment to gifti.relatedFiles.

used

the vertex set changes.

file path for vertex data key.

double-barrelled file extensions.

deprecation warning on access though.

nomenclature.

method to query current vertex set.