[JAVA] Case changes in generated class names since 0cf82d7

Description

Older versions of the retrofit2 generator (2.3.0-SNAPSHOT, possibly earlier) followed the tag case when generating class names, e.g.: AWS Regions -> AWSRegionsApi, AWSRegionsApiTest. As of 2.3.0 this is no longer the case, and class names are more aggressively camel-cased: AwsRegionsApi. Should this be considered a bug?

Swagger-codegen version

2.3.0

Swagger declaration file content or url

swagger: '2.0'
info:
  title: example
  version: 1.0.0
host: 'localhost:8080'
schemes:
  - http
basePath: /
produces:
  - application/json
consumes:
  - application/json
securityDefinitions:
  basic:
    type: basic
security:
  - basic: []
paths:
  /aws-regions:
    get:
      summary: List AWS regions
      operationId: getAwsRegions
      tags:
        - AWS Regions
      responses:
        200:
          description: List of AWS regions supported
          schema:
            type: array
            items:
              $ref: '#/definitions/AwsRegion'
definitions:
  AwsRegion:
    type: object

Command line used for generation

java -jar $HOME/.m2/repository/io/swagger/swagger-codegen-cli/2.3.0/swagger-codegen-cli-2.3.0.jar -i swagger.yml -l java -o . -c codegen.json

{
    "groupId": "com.example",
    "artifactId": "foo-http-client",
    "artifactVersion": "0.0.1-SNAPSHOT",
    "modelPackage": "com.example.httpclient.models",
    "apiPackage": "com.example.httpclient.api",
    "invokerPackage": "com.example.httpclient",
    "serializableModel": true,
    "library": "retrofit2",
    "dateLibrary": "joda",
    "hideGenerationTimestamp": true
}

Related issues/PRs

The change has been introduced by commit 0cf82d7, PR #6399.

Start by reviewing commit 0cf82d7 and related PR #6399, then reproduce Java retrofit2 generation with the supplied Swagger YAML and command. Compare the generated class names with the older 2.3.0-SNAPSHOT behavior; done requires a decided, documented naming expectation and corresponding project changes.