I'd like to add callback functionality to iterative_unfold. These Callback objects would be called after each iteration of unfolding. A couple I can think of off the top of my head are a callback for regularization and a callback for saving iteration info to disk.

Something like

from pyunfold import iterative_unfold, HDFLogger
# Set up callback
hdflogger = HDFLogger('/path/to/outputfile.hdf')
# Pass callback to iterative_unfold
unfolded_result = iterative_unfold(*, callbacks=[hdflogger])