raster image of struct-class-201-t

Tests that the value of the 'class' attribute is included in the DOM, including space-separated values, and values with extraneous spaces.

The rendered picture should match the reference image, except for possible variations in the labelling text (per CSS2 rules). The pass condition is seeing three green circles, with text below each circle reflecting the normalized space-separated values for the class of that circle. The leftmost circle has the value "foo", the middle circle has the value "bar baz", and the rightmost circle has the value " funky spacing ", normalized to "funky spacing". If any of the circles are red, the test has failed.