message: Allow sample weights to be passed in as a Tuple.
diff: @@ -537,16 +537,17 @@ def standardize_sample_or_class_weights(x_weight, output_names, weight_type):
  Raises:
  ValueError: In case of invalid user-provided argument.
  """
  - if x_weight is None or (isinstance(x_weight, list) and len(x_weight) == 0): # pylint: disable=g-explicit-length-test
  + if x_weight is None or (isinstance(x_weight, (list, tuple)) and
  + len(x_weight) == 0): # pylint: disable=g-explicit-length-test
  return [None for _ in output_names]
  if len(output_names) == 1:
  - if isinstance(x_weight, list) and len(x_weight) == 1:
  + if isinstance(x_weight, (list, tuple)) and len(x_weight) == 1:
  return x_weight
  if isinstance(x_weight, dict) and output_names[0] in x_weight:
  return [x_weight[output_names[0]]]
  else:
  return [x_weight]
  - if isinstance(x_weight, list):
  + if isinstance(x_weight, (list, tuple)):
  if len(x_weight) != len(output_names):
  raise ValueError('Provided `' + weight_type + '` was a list of ' +
  str(len(x_weight)) + ' elements, but the model has ' +
  