nl_tokens: TODO remember collapsal path
pl_tokens: function collapse ( evt ) { var collapser = evt . target ; var target = collapser . parentNode . getElementsByClassName ( 'collapsible' ) ; if ( ! target . length ) { return } target = target [ 0 ] ; if ( target . style . display === 'none' ) { var ellipsis = target . parentNode . getElementsByClassName ( 'ellipsis' ) [ 0 ] target . parentNode . removeChild ( ellipsis ) ; target . style . display = '' ; collapser . innerHTML = '-' ; } else { target . style . <mask> = 'none' ; var ellipsis = document . createElement ( 'span' ) ; ellipsis . className = 'ellipsis' ; ellipsis . innerHTML = ' &hellip; ' ; target . parentNode . insertBefore ( ellipsis , target ) ; collapser . innerHTML = '+' ; } }