Class Advlist -superclass Set/KeySetAdvlist instproc add {key element} {    if {[$self member $key] == 1} {	set el [$self findelement $key]	$el union $ element    } else {	$self next $key $element    }    return}Advlist instproc pp {args} {    set desc "Set"    if {[llength $args] == 1} {	set desc [lindex $args 0]    }        set list [$self settolist]    set n [$self numelements]    puts -nonewline "$desc has $n elements. ( "    foreach el $list {	set key [lindex $el 0]	set meta [lindex $el 1]	set metastring [$meta metatostring]	puts -nonewline "($key : $metastring) "    }    puts ")"}Advlist instproc addADV {sender meta} {        $self add $sender [$meta copy]}Advlist instproc findADV {sender} {    return [$self findelement $sender]}