code: function(key) {
        var values = [], relTime;
  
        if(this.options.firstItem === 'name') {
          //need both to support moment ver < 2 and  >= 2
          relTime = moment.relativeTime || moment.langData()._relativeTime; 
          var header = typeof relTime[key] === 'function' ? relTime[key](1, true, key, false) : relTime[key];
          //take last entry (see momentjs lang files structure) 
          header = header.split(' ').reverse()[0];                
          values.push(['', header]);
        } else if(this.options.firstItem === 'empty') {
          values.push(['', '']);
        }
        return values;
      }
docs: /*
  Initialize items of combos. Handles `firstItem` option