Swagger Codegen is a tool for generating server stubs and client SDKs for any API defined with an OpenAPI specification. This is particularly useful when you are following a spec-first API development approach.
When generating the stub code for the backend powering the API, it may not always be desirable to generate stubs for every endpoint in the same module. This will depend on the number of endpoints in your API definition, and your approach to the contents of deployed services (Microservices or otherwise). There does not appear to be a documented way to only generate stubs for some API paths using this tool. There does however appear to be an undocumented one.