Public domain image prepared by Bob Friesenhahn using a development version of GraphicsMagick 1.2. From ftp://ftp.remotesensing.org/pub/libtiff/pics-3.8.0.tar.gz
Add (MM, 1, 1, 1, (4,), ()): ('L', 'L;4'), and sort list
Test for 4-bit TIFF
flake8