message: Raise a more helpful error when steps_per_epoch=None and an INFINITE dataset exists.
diff: @@ -1309,8 +1309,12 @@ class DataHandler(object):
  size = cardinality.cardinality(dataset)
  if size == cardinality.INFINITE and steps is None:
  - raise ValueError("When passing an infinitely repeating dataset, you "
  - "must specify how many steps to draw.")
  + raise ValueError(
  + "When passing an infinitely repeating dataset, please specify a "
  + "`steps_per_epoch` value so that epoch level "
  + "callbacks continue to work. The value can be arbitrary, or a number "
  + "that you think correctly defines the size of an epoch. "
  + "Epoch-level callbacks will then be called at this interval.")
  if size >= 0:
  return size.numpy().item()
  return None
  