# File lib/mongo_mapper/plugins/keys/key.rb, line 59
        def get(value)
          # Special Case: Generate default _id on access
          value = default_value if @is_id and !value

          if @typecast
            klass = typecast_class  # Don't make this lookup on every call
            type.from_mongo(value).map { |v| klass.from_mongo(v) }
          else
            type.from_mongo(value)
          end
        end