'Test xl_range()'

def test_xl_range(self):

    tests = [(0, 0, 9, 0, 'A1:A10'), (1, 2, 8, 2, 'C2:C9'), (0, 0, 3, 4, 'A1:E4'), (0, 0, 0, 0, 'A1:A1'), (0, 0, 0, 1, 'A1:B1'), (0, 2, 0, 9, 'C1:J1'), (1, 0, 2, 0, 'A2:A3'), (9, 0, 1, 24, 'A10:Y2'), (7, 25, 9, 26, 'Z8:AA10'), (1, 254, 1, 255, 'IU2:IV2'), (1, 256, 0, 16383, 'IW2:XFD1'), (0, 0, 1048576, 16384, 'A1:XFE1048577')]
    for (first_row, first_col, last_row, last_col, cell_range) in tests:
        exp = cell_range
        got = xl_range(first_row, first_col, last_row, last_col)
        self.assertEqual(got, exp)
