NEST/Elasticsearch.Net version: 2.3.3

Elasticsearch version: 2.x

Description of the problem including expected versus actual behavior:
I want to use _count api to get the count of results. My current query generation logic uses _search api of ES. The thing is SearchDescriptor for _search api has component ROUTING which is list of strings (and I do need multiple routing strings for my application), while the analogous ROUTING component of CountDescriptor takes string parameter only (you can't pass a list).
The question is : do we have a way to pass multiple routing strings to CountDescriptor by appending all the string using certain separator or any other way to handle it?