message: removed 'optional' string from docstrings
diff: @@ -216,8 +216,8 @@ def check_validation_split_arg(validation_split, subset, shuffle, seed):
  Args:
  shuffle: Whether to shuffle the data. Either True or False.
  - seed: Optional random seed for shuffling and transformations.
  - validation_split: Optional float between 0 and 1,
  + seed: random seed for shuffling and transformations.
  + validation_split: float between 0 and 1,
  fraction of data to reserve for validation.
  subset: One of "training" or "validation".
  Only used if `validation_split` is set.
  