ServiceNow has one of the greatest utility of impersonation. Really good for testing but because of compliance or whatever might be the reason client set that as hidden majorly on production instances. Recently I got the need to impersonate to identify the issue so thanks to one of the community members his post helped. Highly unrecommended!! Here is the solution.
There is also one GlideImpersonate class that we usually use while writing ATF scripts. But in case you want a session then use the functions shown!!
Link For GlideImpersonate Docs: https://developer.servicenow.com/dev.do#!/reference/api/orlando/server_legacy/GlideImpersonateAPI
