[request for clarification]: generating Java from Yaml: multiple "responses", but only one ResponseEntity<...>

The yaml file contains a call like this:

paths:
  /foo/bar:
    get:
...
      responses:
        '200':
          description: OK
          schema:
            $ref: '#/definitions/FooResult'
        '400':
          description: BAD REQUEST
          schema:
            $ref: '#/definitions/FooError'
...

The generated API declares the method as returning a ResponseEntity<FooResult>, and I cannot see how my implementation can ever return a ResponseEntity<FooError> for cases that lead to a code 400.

I'd appreciate explanations, what I may be expecting wrong, or if this is a bug.

Start with the YAML response definitions and the generated Java method described in the report. Determine whether multiple response schemas are supported or documented, then clarify the expected handling of the 400 response and whether a generator change is required.