code: function (posAry, limit, breakOneUp) {
    var numSections = posAry.length;
    var position = Math.ceil(limit / numSections);
  
    return posAry.map(function (seedAry) {
      var unchosen = position;
      // need a match in this section if no clear position-placer
      for (var i = 0; unchosen > 0; i += 1) {
        var xps = seedAry[i];
        var needForBetween = xps.length >1 && xps.length === unchosen && breakOneUp;
        if (xps.length > unchosen || needForBetween) {
          return xps.slice();
        }
        unchosen -= xps.length; // next cluster must be smaller to fit
      }
      return []; // nothing to break this section
    });
  }
docs: ------------------------------------------------------------------ Init helpers ------------------------------------------------------------------