Programmatically login a user in Crowd

[Lokesh Naktode_miniOrange]

I am developing a plugin for the crowd where I need to create user session programmatically and I am stuck right now. Previously, I was using Crowd HTTP authenticator for creating a user session but it is not available from 3.0.0. (You can check the upgrade note from the link below).

https://confluence.atlassian.com/crowd/crowd-3-0-upgrade-notes-905088628.html

So I am looking for the alternative solution(alternative Crowd APIs). Can someone please take a look at it.