code: function selector() {
          whitespace();
  
          while (css[0] === '}') {
              error('extra closing bracket');
          }
  
          const m = match(/^(("(?:\\"|[^"])*"|'(?:\\'|[^'])*'|[^{])+)/);
  
          if (m) {
              return m[0]
                  .trim() // remove all comments from selectors
                  .replace(/\/\*([^*]|[\r\n]|(\*+([^*/]|[\r\n])))*\*\/+/g, '')
                  .replace(/"(?:\\"|[^"])*"|'(?:\\'|[^'])*'/g, function(m) {
                      return m.replace(/,/g, '\u200C');
                  })
                  .split(/\s*(?![^(]*\)),\s*/)
                  .map(function(s) {
                      return s.replace(/\u200C/g, ',');
                  });
          }
      }
docs: Selector -------------------------------------------------------------------------