def _get_last_checkpoint(self):
    rev = self.scm.get_ref(EXEC_CHECKPOINT)
    if rev:
        return rev
    raise DvcException('No existing checkpoint experiment to continue')
def _get_last_checkpoint(self):
    rev = self.scm.get_ref(EXEC_CHECKPOINT)
    if rev:
        return rev
    raise DvcException('No existing checkpoint experiment to continue')