Mary was at that time a nurse for the singer Lena Horne.

Entity and relation annotations:
id: 0
type: entity
value: text: Mary
labels: <Person>
id: 1
type: entity
value: text: Lena Horne
labels: <Person>
id: 2
type: entity
value: text: the singer
labels: <Title>
id: 3
type: entity
value: text: nurse
labels: <Title>
type: relation
to_id: 2
labels: Person:holds_title:Title
from_id: 1
type: relation
to_id: 3
labels: Person:holds_title:Title
from_id: 0