Invalid anonymous model name with non-ascii title

[inferrna]

Example swagger. See broken property

openapi: 3.0.0
servers:
  - url: 'https://todo.vacs.fr/v1'
  - url: 'http://todo.vacs.fr/v1'
info:
  title: Todo API
  description: Todo API
  version: 1.0.0
  termsOfService: 'https://todo.vacs.fr/terms/'
  contact:
    email: Stephane.Carrez@gmail.com
  license:
    name: Apache 2.0
    url: 'http://www.apache.org/licenses/LICENSE-2.0.html'
tags:
  - name: tasks
    description: Tasks
paths:
  /:
    get:
      tags:
        - tasks
      summary: Redirect to the UI
      description: |
        Default operation to redirect to the UI index page.
      operationId: redirectTodos
      responses:
        '302':
          description: redirect to the UI page
  /todos:
    get:
      tags:
        - tasks
      summary: List the available tasks
      description: |
        The list of tasks can be filtered by their status.
      operationId: listTodos
      parameters:
        - name: status
          in: query
          description: Filters the tasks by their status
          required: false
          schema:
            type: string
            enum:
              - done
              - waiting
              - working
              - all
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Todo'
        '400':
          description: Invalid status value
      security:
        - todo_auth:
            - 'read:todo'
security:
  - todo_auth: []
externalDocs:
  description: Find out more about Swagger
  url: 'http://swagger.io'
components:
  securitySchemes:
    todo_auth:
      type: oauth2
      flows:
        password:
          tokenUrl: 'http://localhost:8080/v1/oauth/token'
          scopes:
            'write:todo': Write a todo
            'read:todo': Read a todo
  schemas:
    Todo:
      type: object
      properties:
        broken:
          type: object
          title: "приветики"
          properties:
            testprop:
              type: integer
        id:
          type: integer
          format: int64
          description: The todo identifier
        title:
          type: string
          description: The todo title
        create_date:
          type: string
          format: date-time
          description: The todo creation date
        done_date:
          type: string
          format: date-time
          description: The todo resolution date
        status:
          type: string
          description: The todo state
          enum:
            - waiting
            - working
            - done
      required:
        - id
        - title
        - status
        - create_date
      example:
        id: 23
        title: Make the FOSDEM presentation
        description: password
        status: working
        create_date: '2017-12-24T00:00:00.000Z'
      xml:
        name: Todo

Without title, broken field is naming as TodoBroken.scala, with ascii title it's naming after it. But with any non-ascii title, it just empty.