title: FastAPI - Endpoint returns one of enum values
body: <p>I have an app:</p>
  <pre><code>import enum
  
  from fastapi import FastAPI
  from pydantic import BaseModel
  
  
  class ClientTypeEnum(enum.Enum):
      UL = 1
      IP = 2
      FL = 3
  
  
  class Request(BaseModel):
      text: str
  
  
  app = FastAPI()
  
  
  @app.post('/classify')
  def classify(request: Request):
      return
  </code></pre>
  <p>How can I realize that in swagger one could see that response possible values are values of <strong>ClientTypeEnum</strong>?</p>