I try to import my own shared library inside html.template file but for no success.

During my pipeline I store test and build results inside a Singleton and then I want to format them and send them via mail (using email-ext plugin)

My Problem is :

I can't access variables from outside the template:
@Library('my-lib@emails')_ => not working
import my.lib.JobData => not working
I need an option to access pipeline context from template groovy (${SCRIPT, template="html.template")
in order to format that data