Userdefined Ext.data.Types throws unrecognized alias exception

I created my own 'Type' based on the documentation.

Now when I try to use it I get exception as follow:

Code:

Error: [Ext.createByAlias] Unrecognized alias: data.field.[object Object]
throw new Error("[Ext.createByAlias] Unrecognized alias: " + alias);

Could you please take a look on my fiddle and tell me if I did something wrongly or there is a bug?

Here is my fiddle: http://ift.tt/1AAd2J8

Thanks in advance

Userdefined Ext.data.Types throws unrecognized alias exception