message: Removed unnecessary iterator class from PartitionedVariable
  Note that PartitionedVariable is still iterable.
diff: @@ -2457,34 +2457,6 @@ class PartitionedVariable(object):
  @end_compatibility
  """
  - class PartitionedVariableIterator(object):
  - """An iterator that allows accessing the underlying `Variable` objects.
  -
  - This iterator is necessary to control order of access when Variables
  - are not partitioned in a standard way along a single axis.
  -
  - Allows e.g. `list(partitioned_variable)` to return a proper list.
  - """
  -
  - def __init__(self, partitioned_variable):
  - self._ix = 0
  - self._partitioned_variable = partitioned_variable
  -
  - def __iter__(self):
  - return self
  -
  - def __next__(self): # For python3 compatibility.
  - return self.next()
  -
  - def next(self):
  - # pylint: disable=protected-access
  - if self._ix >= len(self._partitioned_variable._variable_list):
  - raise StopIteration()
  - variable = self._partitioned_variable._variable_list[self._ix]
  - # pylint: enable=protected-access
  - self._ix += 1
  - return variable
  -
  def __init__(self, name, shape, dtype, variable_list, partitions):
  """Creates a new partitioned variable wrapper.
  @@ -2541,7 +2513,7 @@ class PartitionedVariable(object):
  def __iter__(self):
  """Return an iterable for accessing the underlying partition Variables."""
  - return self.PartitionedVariableIterator(self)
  + return iter(self._variable_list)
  def __len__(self):
  num_partition_axes = len(self._partition_axes())
  