docs: function buildNumberUnitMethods() {
    defineInstanceSimilar(sugarNumber, DateUnits, function(methods, unit) {
      var name = unit.name, base, after, before;
      base = function(n) {
        return round(n * unit.multiplier);
      };
      after = function(n, d, options) {
        return advanceDate(createDate(d, options, true), name, n);
      };
      before = function(n, d, options) {
        return advanceDate(createDate(d, options, true), name, -n);
      };
      methods[name] = base;
      methods[name + 's'] = base;
      methods[name + 'Before'] = before;
      methods[name + 'sBefore'] = before;
      methods[name + 'Ago'] = before;
      methods[name + 'sAgo'] = before;
      methods[name + 'After'] = after;
      methods[name + 'sAfter'] = after;
      methods[name + 'FromNow'] = after;
      methods[name + 'sFromNow'] = after;
    });
  }