code: function comment() {
          whitespace();
  
          if (css[0] !== '/' || css[1] !== '*') {
              return;
          }
  
          let i = 2;
  
          while (css[i] && (css[i] !== '*' || css[i + 1] !== '/')) {
              i++;
          }
  
          if (!css[i]) {
              return error('end of comment is missing');
          }
  
          const str = css.slice(2, i);
  
          css = css.slice(i + 2);
  
          return {
              type   : 'comment',
              comment: str
          };
      }
docs: Comments -------------------------------------------------------------------------