Case T-442/17 RENV: Judgment of the General Court of 16 December 2020 — RN v Commission (Civil service — Officials — Surviving spouse — Survivor’s pension — Articles 18 and 20 of Annex VIII to the Staff Regulations — Conditions for eligibility — Duration of the marriage — Plea of illegality — Equal treatment — Principle of non-discrimination on grounds of age — Proportionality — Concept of ‘spouse’)