How do I save (export) all layers with gimp's script fu?

Question

With gimp fu, I can save the content of one layer (at least, that is how I interprete the definition of gimp_file_save because it takes the parameter

Answer 1

I have found out that if you pass None as the drawable argument to gimp_xcf_save(), GIMP (at least version 2.8) will save all layers of the image to the XCF file:

pdb.gimp_xcf_save(0, image, None, 'file.xcf', 'file.xcf')