def METHOD_NAME(self, desc, data, top, exp ):
    g = urwid.BarGraph( ['black','red','blue'],
            None, {(1,0):'red/black', (2,1):'blue/red'})
    g.set_data( data, top )
    rval = g.calculate_display((5,3))
    assert rval == exp, f"{desc} expected {exp!r}, got {rval!r}"