Missing `iter_type` kwarg in `morphio.Morphology.iter`

[eleftherioszisis]

import morphio

m1 = morphio.mut.Morphology()
m1.iter(morphio.IterType.depth_first)  # works
m1.iter(iter_type=morphio.IterType.depth_first)  # works

m2 = m1.as_immutable()
m2.iter(morphio.IterType.depth_first)  # works
m2.iter(iter_type=morphio.IterType.depth_first)  # fails

Traceback:

TypeError                                 Traceback (most recent call last)
<ipython-input-6-ab9de27952d8> in <module>
      7 m2 = m1.as_immutable()
      8 m2.iter(morphio.IterType.depth_first)  # works
----> 9 m2.iter(iter_type=morphio.IterType.depth_first)  # fails

TypeError: iter(): incompatible function arguments. The following argument types are supported:
    1. (self: morphio._morphio.Morphology, Section iterator that runs successively on every neurite
iter_type controls the order of iteration on sections of a given neurite. 2 values can be passed:
- morphio.IterType.depth_first (default)
- morphio.IterType.breadth_first (default)
iter_type: morphio._morphio.IterType = <IterType.depth_first: 0>) -> Iterator

Invoked with: <morphio._morphio.Morphology object at 0x7f3df81e73b0>; kwargs: iter_type=<IterType.depth_first: 0>