Checks whether a V1 or V2 checkpoint exists with the specified prefix. (deprecated)
This is the recommended way to check if a checkpoint exists, since it takes
into account the naming difference between V1 and V2 formats.
the prefix of a V1 or V2 checkpoint, with V2 taking
priority. Typically the result of
Saver.save() or that of
tf.train.latest_checkpoint(), regardless of sharded/non-sharded or
A bool, true if a checkpoint referred to by