Use LinkedHashMap instead of HashMap for Swagger dictionary type (Java codegen)?

I'm using openapi 3.0.2, and the codegen plugin:

<groupId>io.swagger.codegen.v3</groupId>
<artifactId>swagger-codegen-maven-plugin</artifactId>
<version>3.0.14</version>

I'm using the swagger dictionary/hashmap type described here:

https://swagger.io/docs/specification/data-models/dictionaries/

openapi: "3.0.2"
...
Labels:
	type: object
	additionalProperties:
		type: string
		minLength: 1
	description:  A description.

When I generate Java code for this, it is modelled as a class which extends HashMap:

@ApiModel(description = "A description.")
@Validated
@javax.annotation.Generated(value = "io.swagger.codegen.v3.generators.java.SpringCodegen", date = "2020-02-26T12:17:36.248Z[Europe/London]")
public class Labels extends HashMap<String, String>  {
...
}

Is there any way to instruct swagger to use a LinkedHashMap instead of a HashMap? (without having to exclude this class from codegen and manually modify it).

I would like to control the ordering of the entries in this dictionary when returning it to clients.

Related: https://github.com/swagger-api/swagger-core/issues/2021

Start with the swagger-codegen-maven-plugin 3.0.14 and its Java codegen path, since no specific files or tests are named. Trace how the OpenAPI additionalProperties dictionary becomes a Java HashMap and identify whether the map type can be configured. Done means generated dictionary models use LinkedHashMap without manual edits.