Hello, below is a sample program that reproduces the error.

import networkit as nk
g = nk.graph.Graph(directed=True)
g.addNode()
g.addNode()
g.addEdge(0,1)
print(g.nodes())        # "[0, 1]"
print(g.inNeighbors(0)) # "[]"
print(g.inNeighbors(1)) # Error here!

On the final line of code, when node 1's in-neighbors are requested, I get the following error:

Traceback (most recent call last):
  File "Untitled.py", line 10, in <module>
    print(g.inNeighbors(1))
  File "networkit/_NetworKit.pyx", line 1061, in networkit._NetworKit.Graph.inNeighbors
  File "networkit/_NetworKit.pyx", line 1154, in networkit._NetworKit.Graph.forInEdgesOf
RuntimeError: An Exception occurred, aborting execution of iterator: lambda1() takes exactly one argument (4 given)

I've been playing around with this for a while and I've been unable to get it to work. Just thought I would bring it up so it can be addressed unilaterally soon.