don't try to call a private method from a job
don't try to call a private method from a job

fixes #CNVS-2952

test plan:
- in a production environment, change an assignment date
- it should work

Change-Id: Ief63c9f69bd33ca8f998bac4ecc487f82e105e7b
Reviewed-on: https://gerrit.instructure.com/16806
QA-Review: Amber Taniuchi <ef4bfd1e6d278f6bc7d4a478f02be2cb9581a0a5@instructure.com>
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Stanley Stuart <d3942c3cf0aa13de8a95b690bdc33eab29ac4e73@instructure.com>

arrivu/hoodemo,wimemx/Canvas,arrivu/arrivu-lms,sfu/canvas-lms,antoniuslin/canvas-lms,roxolan/canvas-lms,grahamb/canvas-lms,fronteerio/canvas-lms,utkarshx/canvas-lms,greyhwndz/canvas-lms,greyhwndz/canvas-lms,arrivu/qibla-ecampus,arrivu/arrivu-lms,skmezanul/canvas-lms,parbros/red-innovadores-lms,landonwilkins/canvas-lms,redconfetti/canvas-lms,nditech/red-innovadores-lms,arrivu/hoodemo,HotChalk/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,wye0220/shindig-canvas,tgroshon/canvas-lms,greyhwndz/canvas-lms,loganrun/pincan,Jyaasa/canvas-lms,djbender/canvas-lms,HotChalk/canvas-lms,Jyaasa/canvas-lms,ShreniiNepal/shrenii_lmp,sfu/canvas-lms,sdeleon28/canvas-lms,juoni/canvas-lms,venturehive/canvas-lms,usmschuck/canvas,loganrun/pincan,juoni/canvas-lms,sfu/canvas-lms,parbros/red-innovadores-lms,merichar/canvas-lms,jay3126/canvas-lms,shidao-fm/canvas-lms,kyroskoh/canvas-lms,fronteerio/canvas-lms,tgroshon/canvas-lms,Unow/canvas-lms,juoni/canvas-lms,sdeleon28/canvas-lms,ShreniiNepal/shrenii_lmp,rup/Tarrax,ShreniiNepal/shrenii_lmp,sli7246/canvas_branch,sdeleon28/canvas-lms,leftplusrightllc/canvas-lms,ShreniiNepal/shrenii_lmp,arrivu/jigsaw-lms,redconfetti/canvas-lms,leftplusrightllc/canvas-lms,shidao-fm/canvas-lms,Unow/canvas-lms,sfu/canvas-lms,wrdsb/canvas-lms,venturehive/canvas-lms,tgroshon/canvas-lms,skmezanul/canvas-lms,skmezanul/canvas-lms,antoniuslin/canvas-lms,wrdsb/canvas-lms,kyroskoh/canvas-lms,Unow/ins,sli7246/canvas_branch,Rvor/canvas-lms,greyhwndz/canvas-lms,whalejasmine/canvas-lms,jay3126/canvas-lms,SwinburneOnline/canvas-lms,merichar/canvas-lms,antoniuslin/canvas-lms,arrivu/arrivu-lms,Unow/ins,redconfetti/canvas-lms,efrj/canvas-lms,jay3126/canvas-lms,wye0220/shindig-canvas,antoniuslin/canvas-lms,rup/Tarrax,SwinburneOnline/canvas-lms,wrdsb/canvas-lms,whalejasmine/canvas-lms,wrdsb/canvas-lms,samuels410/greatlakes-lms,wimemx/Canvas,roxolan/canvas-lms,va7map/canvas-lms,HotChalk/canvas-lms,skmezanul/canvas-lms,arrivu/qibla-ecampus,tgroshon/canvas-lms,kyroskoh/canvas-lms,utkarshx/canvas-lms,arrivu/hoodemo,merichar/canvas-lms,landonwilkins/canvas-lms,shidao-fm/canvas-lms,roxolan/canvas-lms,nditech/red-innovadores-lms,usmschuck/canvas,landonwilkins/canvas-lms,djbender/canvas-lms,landonwilkins/canvas-lms,grahamb/canvas-lms,sli7246/canvas_branch,Rvor/canvas-lms,va7map/canvas-lms,usmschuck/canvas,grahamb/canvas-lms,redconfetti/canvas-lms,Unow/canvas-lms,djbender/canvas-lms,samuels410/greatlakes-lms,rup/Tarrax,roxolan/canvas-lms,va7map/canvas-lms,leftplusrightllc/canvas-lms,samuels410/greatlakes-lms,nditech/red-innovadores-lms,fronteerio/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,wimemx/Canvas,efrj/canvas-lms,utkarshx/canvas-lms,whalejasmine/canvas-lms,kyroskoh/canvas-lms,sfu/canvas-lms,Unow/ins,efrj/canvas-lms,Jyaasa/canvas-lms,sdeleon28/canvas-lms,fronteerio/canvas-lms,juoni/canvas-lms,whalejasmine/canvas-lms,arrivu/jigsaw-lms,Jyaasa/canvas-lms,Rvor/canvas-lms,grahamb/canvas-lms,wye0220/shindig-canvas,venturehive/canvas-lms,utkarshx/canvas-lms,efrj/canvas-lms,arrivu/qibla-ecampus,parbros/red-innovadores-lms,Rvor/canvas-lms,arrivu/jigsaw-lms,samuels410/greatlakes-lms,SwinburneOnline/canvas-lms,SwinburneOnline/canvas-lms,usmschuck/canvas,nditech/red-innovadores-lms,loganrun/pincan,jay3126/canvas-lms,leftplusrightllc/canvas-lms,venturehive/canvas-lms,va7map/canvas-lms,shidao-fm/canvas-lms