[cctbxbb] Adding columns to new *unmerged* MTZ object

Hi Folks, I am trying to create a new MTZ file containing unmerged and it seems to be less simple than I would think - set_reals() on a column requires a set of Miller indices and values and does a lookup internally (which I don’t want for unmerged values) and set_values() requires that the array is already the right size - when it starts off as size 0 and I have no idea how to make enough room in there from the Python API… Any clues? I have done quite a chunk of grepping around to try and figure this one out and have run out of ideas… Thanks Graeme