message: Getting rid of obsolete function is_variable_registered from LayerCollection.  Replaced it with a simple function that returns a list of all the registered variables.
diff: @@ -152,19 +152,13 @@ class LayerCollection(object):
  """LossFunctions registered with this LayerCollection."""
  return list(self._loss_dict.values())
  - def is_variable_registered(self, variable):
  - """Checks whether the variable has already been registered.
  -
  - Args:
  - variable: A single variable or tensor.
  - Returns:
  - True if the variable has been registered either by itself or as part of a
  - tuple.
  - """
  - return any([
  - variable in key if isinstance(key, (tuple, list)) else variable == key
  - for key in self.fisher_blocks.keys()
  - ])
  + @property
  + def registered_variables(self):
  + """A tuple of all of the variables currently registered."""
  + tuple_of_tuples = (ensure_sequence(key) for key, block
  + in six.iteritems(self.fisher_blocks))
  + flat_tuple = tuple(item for tuple_ in tuple_of_tuples for item in tuple_)
  + return flat_tuple
  @property
  def linked_parameters(self):
  