Case T-864/19: Judgment of the General Court of 13 July 2022 — AI and Others v ECDC (Civil service — ECDC staff members — Psychological harassment — Request for assistance — Prior warnings — Article 31 of the Charter of Fundamental Rights — Article 24 of the Staff Regulations — Scope of the duty to provide assistance — Duty to have regard for the welfare of officials — Opening of an investigation — Reasonable time period — Liability — Unlawfulness)