openapi: 3.0.1
paths:
  /test:
    summary: test
info:
  description: test
  version: 1.0.0
  title: test
components:
  schemas:
    Type:
      properties:
        prop:
          nullable: true
          enum: [A, B, C]
          type: string
        prop2:
          enum: [A, B, C, null]
          type: string
        prop3:
          nullable: true
          enum: []
          type: string