Globs for the checkpoints pointed to by checkpoint_prefixes. If the files
exist, collect their mtime. Both V2 and V1 checkpoints are considered, in
that priority.
This is the recommended way to get the mtimes, since it takes into account
the naming difference between V1 and V2 formats.
Args
checkpoint_prefixes
a list of checkpoint paths, typically the results of
Saver.save() or those of tf.train.latest_checkpoint(), regardless of
sharded/non-sharded or V1/V2.
Returns
A list of mtimes (in microseconds) of the found checkpoints.