JvmPackageNameMustBeValidNameImpl(
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }
    add(FirJvmErrors.JVM_PACKAGE_NAME_NOT_SUPPORTED_IN_FILES_WITH_CLASSES) { firDiagnostic ->
        JvmPackageNameNotSupportedInFilesWithClassesImpl(
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }

                *path operations* in this router.

                Read more about it in the
                [FastAPI docs for Bigger Applications - Multiple Files](https://fastapi.tiangolo.com/tutorial/bigger-applications/#include-an-apirouter-with-a-custom-prefix-tags-responses-and-dependencies).

                **Example**

                ```python