You can't keep a Canon in a cello case, but a Nikon might fit.

Also, if you have the cultural appreciation to be a cellist, you might wish to put wine in it, in which case there would be no room for Blue Nun.

Reminds me of when Jeremy Clarkson did a series of documentaries about our European neighbours. When in France, he found the vineyard where they sell the pulp to the factory that makes Blue Nun. He cupped some grapes in his hand, looked at the camera and said, "See these? This time next year they will be on a dining table in Rotherham."