47     assert!(parse(filter::parse, "brightness(0)").is_ok());  in test_parse_factor()
48     assert!(parse(filter::parse, "brightness(55)").is_ok());  in test_parse_factor()
49     assert!(parse(filter::parse, "brightness(100)").is_ok());  in test_parse_factor()
51     assert!(parse(filter::parse, "contrast(0)").is_ok());  in test_parse_factor()
52     assert!(parse(filter::parse, "contrast(55)").is_ok());  in test_parse_factor()
53     assert!(parse(filter::parse, "contrast(100)").is_ok());  in test_parse_factor()
55     assert!(parse(filter::parse, "grayscale(0)").is_ok());  in test_parse_factor()
56     assert!(parse(filter::parse, "grayscale(55)").is_ok());  in test_parse_factor()
57     assert!(parse(filter::parse, "grayscale(100)").is_ok());  in test_parse_factor()
59     assert!(parse(filter::parse, "invert(0)").is_ok());  in test_parse_factor()
60     assert!(parse(filter::parse, "invert(55)").is_ok());  in test_parse_factor()
61     assert!(parse(filter::parse, "invert(100)").is_ok());  in test_parse_factor()
63     assert!(parse(filter::parse, "opacity(0)").is_ok());  in test_parse_factor()
64     assert!(parse(filter::parse, "opacity(55)").is_ok());  in test_parse_factor()
65     assert!(parse(filter::parse, "opacity(100)").is_ok());  in test_parse_factor()
67     assert!(parse(filter::parse, "sepia(0)").is_ok());  in test_parse_factor()
68     assert!(parse(filter::parse, "sepia(55)").is_ok());  in test_parse_factor()
69     assert!(parse(filter::parse, "sepia(100)").is_ok());  in test_parse_factor()
71     assert!(parse(filter::parse, "saturate(0)").is_ok());  in test_parse_factor()
72     assert!(parse(filter::parse, "saturate(55)").is_ok());  in test_parse_factor()
73     assert!(parse(filter::parse, "saturate(100)").is_ok());  in test_parse_factor()
89     assert!(parse(box_shadow::parse, "1px 1px 0").is_ok());// for zero  in blur_radius_should_not_accept_negavite_values()
90     assert!(parse(box_shadow::parse, "1px 1px 1px").is_ok());// for +ve value  in blur_radius_should_not_accept_negavite_values()