[Pharo-users] instantiate Sparta canvas?

canvas := SpartaCanvas extent: 400@250 This fails even though the documentation says: ''I am an abstract class and should not be instantiated. However, the best way to create an instance of sparta canvas is to send extent: message.'' !! Example: Create an empty canvas of size 400@250: [[[language=smalltalk canvas := SpartaCanvas extent: 400@250. ]]] So, how do instantiate and display a Sparta canvas? Where can I find good documentation about Sparta? Thanks. David