[BUG] [SWIFT] OneOf Code Gen

Hi All

I have a project where the YML has alot of oneOf's in it (see example below)
The swift generated code creates a callback type of 'oneofarrayarrayarray' but doesnt define the type anywhere

Is this a bug or a limitation of the swift code gen

$ openapi-generator version
4.1.0

One example of the YML

'/areas/{id}':
    get:
      tags:
        - areas
      summary: "Retrieve an Area by ID"
      operationId: getAreasById
      parameters:
        - $ref: '#/components/parameters/id'
        - $ref: '#/components/parameters/areaName'
        - $ref: '#/components/parameters/modelType'
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                oneOf:
                - type: array
                  items:
                    $ref: '#/components/schemas/areaLite'
                - type: array
                  items:
                    $ref: '#/components/schemas/areaBasic'
                - type: array
                  items:
                    $ref: '#/components/schemas/areaFull'
              example:
                 - areaLite:
                      $ref: '#/components/schemas/areaLite'
                 - areaBasic:
                      $ref: '#/components/schemas/areaBasic'
                 - areaFull: 
                      $ref: '#/components/schemas/areaFull'

Code Gen Output

    open class func getAreasWithRequestBuilder(propertyId: Int, limit: Int? = nil, modelType: ModelType_getAreas? = nil, offset: Int? = nil, modifiedSince: Date? = nil, sort: String? = nil) -> RequestBuilder<OneOfarrayarrayarray> {
        let path = "/areas"
        let URLString = OpenAPIClientAPI.basePath + path
        let parameters: [String:Any]? = nil
        
        var url = URLComponents(string: URLString)
        url?.queryItems = APIHelper.mapValuesToQueryItems([
            "limit": limit?.encodeToJSON(), 
            "modelType": modelType?.rawValue, 
            "offset": offset?.encodeToJSON(), 
            "propertyId": propertyId.encodeToJSON(), 
            "modifiedSince": modifiedSince?.encodeToJSON(), 
            "sort": sort
        ])

        let requestBuilder: RequestBuilder<OneOfarrayarrayarray>.Type = OpenAPIClientAPI.requestBuilderFactory.getBuilder()

        return requestBuilder.init(method: "GET", URLString: (url?.string ?? URLString), parameters: parameters, isBody: false)
    }

My workaround (will get annoying every time they update their API)

    public enum responseTest : Codable {
        case basic(PropertiesBasic)
        case lite(PropertiesLite)
        case full(PropertiesFull)
    }

Reproduce the issue with the supplied oneOf schema using openapi-generator version 4.1.0, then inspect the Swift generator output around RequestBuilder. Done means the generated Swift output defines a usable response type instead of referencing an undefined type, or clearly establishes that the schema is unsupported.