leaveContext = () => {
  const len = disabledElems.length
  const dataStorage = svgCanvas.getDataStorage()
  if (len) {
    for (let i = 0; i < len; i++) {
      const elem = disabledElems[i]
      const orig = dataStorage.get(elem, 'orig_opac')
      if (orig !== 1) {
        elem.setAttribute('opacity', orig)
      } else {
        elem.removeAttribute('opacity')
      }
      elem.setAttribute('style', 'pointer-events: inherit')
    }
    disabledElems = []
    svgCanvas.clearSelection(true)
    svgCanvas.call('contextset', null)
  }
  svgCanvas.setCurrentGroup(null)
}
Return from a group context to the regular kind, make any previously
disabled elements enabled again.
@function module:draw.leaveContext
@fires module:svgcanvas.SvgCanvas#event:contextset
@returns {void}