Interface
ILayerDefinition in rest API defines Relationship as any
So LayerRelationship is defined by the actual response from rest API
JSAPI's Relationship class has the same properties as layerDefinition.relationships
returned from rest API:
https://developers.arcgis.com/javascript/latest/api-reference/esri-layers-support-Relationship.html
Difference is the value naming in cardinality
and role
, see below: