code: function(obj) {
        var self = this, arr = obj.start && obj.end ? [obj.start, obj.end] : [obj];
        return arr.every(function(d) {
          return d >= self.start && d <= self.end;
        });
      }
docs: *
  @method contains(<d>)
  @returns Boolean
  @short Returns true if <d> is contained inside the DateRange. <d> may be a date or another DateRange.
  @example
  
  Date.range('2003', '2005').contains(Date.create('2004')) -> true
  
  *