set extraarg {a & b \1 \0 \\1 \\0 \} $ [ ] }
test htmlparse-11.0 {metachar callback} {
    set tags [list]
    htmlparse::parse -cmd [list cb $extraarg] -vroot html {<a b="a">x</a>}
    set tags
}  [list \
     [list $extraarg html {} {} {}] \
     [list $extraarg a    {} {b="a"} {x}] \
     [list $extraarg a    /  {} {}] \
     [list $extraarg html /  {} {}] ]

