how to use -Dapis flag

Description

I'm trying to figure out how to use the -Dapis flag to filter the api paths being generated, but I can't seem to figure it out. And it's not documented with the other examples in https://github.com/swagger-api/swagger-codegen#selective-generation

Swagger-codegen version

3.0.30

Swagger declaration file content or url

https://petstore.swagger.io/v2/swagger.json

Command line used for generation

I've tried a few different things - none of them seem to work:

• java -Dapis="/pet/{petId}/uploadImage" -jar swagger-codegen-cli.jar generate -l go -i https://petstore.swagger.io/v2/swagger.json -o test
• java -Dapis="/pet" -jar swagger-codegen-cli.jar generate -l go -i https://petstore.swagger.io/v2/swagger.json -o test

Using the path tag (but capitalized for some reason, lowercase doesn't work) does generate all code for api path methods with that tag:
java -Dapis="Pet" -jar swagger-codegen-cli.jar generate -l go -i https://petstore.swagger.io/v2/swagger.json -o test
but I'd like to filter to a subset of these methods, if possible.

Suggest a fix/enhancement

Ideally, we could document how to use the -Dapis flag to filter apis.

reference

flag handling code appears to be here:

https://github.com/swagger-api/swagger-codegen/blob/1c5b1ab00e05f8256b2f2df32b1b784a9b365978/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultGenerator.java#L464

Start with the selective-generation section in the Swagger Codegen README and the flag-handling code in modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultGenerator.java around line 464. Use the provided Petstore specification and Go generation commands to verify the documented -Dapis syntax and whether path-level filtering is supported. Done means the README clearly explains the flag's accepted values and limitations.