Tests SVG fragments defined in an external file are invoked with the 'use' element.
The test is passed if the following objects are rendered:
- Right top; square with red fill and blue stroke
- Right middle; square with black fill
- Right bottom; the letters 'A' in blue, 'B' in red, 'C' in blue
- Left top; square with red fill and a circle in the middle with a blue fill
- Left middle; square with green fill
- Left bottom; square with green transparent fill with an overlapping circle with a blue transparent fill.
