gsvm: Added docstring for canvas.
gsvm: Added docstring for canvas.

Signed-off-by: Jakub Novak <3db738bfafc513cdba5d3154e6b5319945461327@gmail.com>

JakubNvk/school,JakubNvk/school,JakubNvk/school,JakubNvk/school,JakubNvk/school,JakubNvk/school