code: function scopifySelectors(selectors, scope_id) {
    var scoper = `[data-${dasherize(scopedStyleIdsProp)}~=${scope_id}]`;
    return [].concat(
      selectors.split(',')
        .map(selector => {
          var [head, ...tail] = selector.trim().split(/([\s+>~])/).filter(Boolean);
          return [
            `${scoper} ${selector}`,
            [`${head}${scoper}`, ...tail].join('')
          ];
        })
    ).join(',');
  }
docs: "Scopify" a set of selectors to an element identifed by a data-scoped-style-ids attribute. Each selector is turned into two selectors. The first places the `[data-...]` selector in front, to address descendnats. The second attaches it to the first subselector, to address the element itself.