Tests that WebInspector.CSSStyleSheet methods work as expected.

h1: [user-agent] {
    ['display':'block'] @[undefined-undefined] 
    ['font-size':'2em'] @[undefined-undefined] 
    ['margin-block-start':'0.67em'] @[undefined-undefined] 
    ['margin-block-end':'0.67em'] @[undefined-undefined] 
    ['margin-inline-start':'0px'] @[undefined-undefined] 
    ['margin-inline-end':'0px'] @[undefined-undefined] 
    ['font-weight':'bold'] @[undefined-undefined] 
}
address, blockquote, center, div, figure, figcaption, footer, form, header, hr, legend, listing, main, p, plaintext, pre, summary, xmp, article, aside, h1, h2, h3, h4, h5, h6, hgroup, nav, section, search, table, caption, colgroup, col, thead, tbody, tfoot, tr, td, th, dir, dd, dl, dt, menu, ol, ul, li, bdi, output, [dir="ltr" i], [dir="rtl" i], [dir="auto" i]: [user-agent] {
    ['unicode-bidi':'isolate'] @[undefined-undefined] 
}
html #inspected.bar, b: [regular, 2:31-3:31; 4:16-5:16] {
    ['text-decoration':'none'] @[6:10-6:32] 
    ['text-decoration-line':'none'] @[undefined-undefined] 
    ['text-decoration-thickness':'initial'] @[undefined-undefined] 
    ['text-decoration-style':'initial'] @[undefined-undefined] 
    ['text-decoration-color':'initial'] @[undefined-undefined] 
}