minProperties and maxProperties null values while reading from swagger 2.0

Consider the following swagger 2.0 file (simplified version of petstore)

swagger: '2.0'
info:
  description: 'This is a sample server Petstore server.  You can find out more about Swagger at [http://swagger.io](http://swagger.io) or on [irc.freenode.net, #swagger](http://swagger.io/irc/).  For this sample, you can use the api key `special-key` to test the authorization filters.'
  version: 1.0.6
  title: Swagger Petstore
  termsOfService: http://swagger.io/terms/
  contact:
    email: apiteam@swagger.io
  license:
    name: Apache 2.0
    url: http://www.apache.org/licenses/LICENSE-2.0.html
host: petstore.swagger.io
basePath: /v2
paths:
  /pet/{petId}:
    get:
      summary: Find pet by ID
      description: Returns a single pet
      operationId: getPetById
      produces:
        - application/json
        - application/xml
      parameters:
        - name: petId
          in: path
          description: ID of pet to return
          required: true
          type: integer
          format: int64
      responses:
        '200':
          description: successful operation
          schema:
            $ref: '#/definitions/Pet'
        '400':
          description: Invalid ID supplied
        '404':
          description: Pet not found
definitions:
  Pet:
    type: object
    required:
      - name
      - photoUrls
    additionalProperties: true
    minProperties: 1
    maxProperties: 4
    properties:
      id:
        type: integer
        format: int64
      name:
        type: string
        example: doggie
      photoUrls:
        type: array
        xml:
          wrapped: true
        items:
          type: string
          xml:
            name: photoUrl
      status:
        type: string
        description: pet status in the store
        enum:
          - available
          - pending
          - sold

If I try to parse as follow

        ParseOptions parseOptions = new ParseOptions();
        parseOptions.setResolve(true); // implicit
        SwaggerParseResult result = new OpenAPIParser().readLocation(f.getAbsolutePath(),null,parseOptions);
        OpenAPI swagger = result.getOpenAPI();

I found that the minProperties and maxProperties field of Pet object are null.

Start at OpenAPIParser.readLocation with ParseOptions.setResolve(true), then trace how the Swagger 2.0 Pet schema is mapped into the OpenAPI model. Use the supplied document to verify whether minProperties and maxProperties are retained on the parsed Pet object, and confirm the fields are no longer null.