Johnson has represented El Salvador at Davis Cup.

Entity and relation annotations:
id: 0
type: entity
value: text: Johnson
labels: <Person>
id: 1
type: entity
value: text: Davis Cup
labels: <Event>
id: 2
type: entity
value: text: El Salvador
labels: <Location>
type: relation
to_id: 1
labels: Person:participates_in:Event
from_id: 0