Collection of structured assay records. Each assay is linked to the Key Event it was extracted for through ke-id (the Key Event GUID). The optional lookup section maps the GUIDs to stable, human-readable ids. This element is for documentation only — it shows the proposed extension to the key-event sequence. In the actual schema, the content below should be inserted inside the existing key-event complexType/sequence, after the existing measurement-methodology element. Legacy free-text field. Retained for backward compatibility. New content should be added to measurement-methods instead. Structured replacement/extension for measurement-methodology. Contains one method element per distinct assay described. Aligned with Methods2AOP framework (Karmaus et al. 2025). One structured record per assay. Multiple method elements within one measurement-methods block represent distinct assays measured for this Key Event.