OpenAPI inheritance

openapi.yaml

components:
  schemas:
    User:
      title: User
      description: User Model
      type: object
      properties:
        id:
          type: integer
        firstName:
          type: string
    UserEx:
      title: 'Ex.User'
      allOf:
        - $ref: '#/components/schemas/User'
        - type: object
          properties:
            surname:
              type: string
      description: Extends User Model