Response headers visually not marked required

Q&A (please complete the following information)

• OS: Windows 10
• Browser: Firefox
• Version: 68.8.0esr
• Method of installation: unpkg.com
• Swagger-UI version: //unpkg.com/swagger-ui-dist@3/swagger-ui-bundle.js
• Swagger/OpenAPI version: OpenAPI 3.0

Content & configuration

Example Swagger/OpenAPI definition:

components:
  responses
    recordCreated:
      description: The item record has been created
      headers:
        Location:
          $ref: "#/components/headers/location"
        ETag:
          $ref: "#/components/headers/etag"
  headers:
    etag:
     description: The entity tag identifying a resource's representational state.
     required: true
     schema:
       type: string
    location:
      description: The URI which points to resource location.
      schema:
        type: string
        format: uri

Describe the bug you're encountering

The response header required property is visually not reflected in the rendered web UI

Expected behavior

I expected to see an asterisk or similar just like for request headers

Screenshots

Start by loading the provided OpenAPI 3.0 definition in Swagger UI and comparing the rendered response headers with request headers. Trace the response-header rendering entry point and make the required ETag header visibly marked like required request headers; done when the example shows that distinction consistently.