old_contents: from fastapi import FastAPI
  from starlette.responses import Response
  
  app = FastAPI()
  
  
  @app.get("/legacy/")
  def get_legacy_data():
      data = """
      <?xml version="1.0"?>
      <shampoo>
      <Header>
          Apply shampoo here.
      <Header>
      <Body>
          You'll have to use soap here.
      </Body>
      </shampoo>
      """
      return Response(content=data, media_type="application/xml")
  
new_contents: from fastapi import FastAPI
  from starlette.responses import Response
  
  app = FastAPI()
  
  
  @app.get("/legacy/")
  def get_legacy_data():
      data = """<?xml version="1.0"?>
      <shampoo>
      <Header>
          Apply shampoo here.
      </Header>
      <Body>
          You'll have to use soap here.
      </Body>
      </shampoo>
      """
      return Response(content=data, media_type="application/xml")
  
subject: Fix XML example (#710)