Reads a preset Relationships key: a relationship ID, a related entity name, or <Child>.<JoinField>. An entity name may itself contain a dot, so the part before the last dot is taken as the child only when isEntity knows it.
Relationships
<Child>.<JoinField>
isEntity
Reads a preset
Relationshipskey: a relationship ID, a related entity name, or<Child>.<JoinField>. An entity name may itself contain a dot, so the part before the last dot is taken as the child only whenisEntityknows it.