loopback/test/fixtures/simple-integration-app/common/models/physician.json

{
  "name": "physician",
  "properties": {
    "name": "string"
  },
  "relations": {
    "patients": {
      "model": "patient",
      "type": "hasMany",
      "through": "appointment",
      "foreignKey": "patientId"
    }
  }
}