Create new casacore images results in empty pixel unit

[rstofi]

When I create an image from a NumPy array and coordinates object, the pixel units are missing, and I can't find a way to add (or change) pixel units in the images module.

I can go around this by opening an image as a table and add the units keyword with the corresponding value, but it seems to be a non-optimal solution.

Is it possible to add a putunit() functionality to the images module?