Pyimagej Installation instructions wrong

I followed directly the instructions on https://github.com/imagej/pyimagej
to instal pyimagej on a Windows 10 system with a fesh conda environment. At first, neither the conda nor pip installation not work, but downgrading helped: pip install imglyb=0.3.5
Some of the imagej distributions used in the imagej.init() are having problems (09:17:15.870 [SciJava-74cadd41-Thread-0] DEBUG loci.formats.ClassList - Could not find loci.formats.in.URLReader and a couple more for the fiji distribution), but that aside, the main problem is that the test code provided on the installation page seems wrong, as the last line yields an error:

>>> ij.op().filter().frangiVesselness(ij.py.to_java(vessels), ij.py.to_java(img), [1, 1], 20)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'net.imagej.ops.OpService' object has no attribute 'filter'
````Preformatted text`

Curtis send me via email some working code, but this is not the case on my installation (same error: 

ij.op().filter
Traceback (most recent call last):
File “”, line 1, in
AttributeError: ‘net.imagej.ops.OpService’ object has no attribute ‘filter’

however, ij.ui().showUI()  works fine as does ij.py.show(img).