code: function(callback) {
              if (callback) { 
                  var _this = this
                  var name = this.name
                  var keys
  
                  this.indexer.all(function(data) {
                      keys = data.map(function(r) {
                         return r.replace(name + '.', '')   
                      })
  
                      _this.fn('keys', callback).call(_this, keys)
                  })
              }
              return this
          }
docs: accepts [options], callback