def render_tag(self, context, run, environment, varname):
        completion = run.completion_single_env(environment)
        context[varname] = completion
        # context[varname] = "{0}and{1}".format(run, environment)
        # context[varname] = "foo"
        return u""
Get/construct completion percentage
dataset/ETHPy150Open mozilla/moztrap/moztrap/view/runtests/templatetags/execution.py/CompletionFor.render_tag