Android : Fetching all the contacts in phone using Cordova plugin

I am developing a Sencha Touch + Cordova application. I need to get all the device contacts in an android phone.

According to the documentation, if we put,

options.filter = ""

It should return all the contacts of the phone. But it does not work. And if I put some other string as the filter, for example,

options.filter = "A"

I get results according to the filter.

Could someone help me to find out what am I doing wrong here?

Thank you