There's error model defined in https://github.com/microsoft/typespec/blob/main/packages/http-specs/specs/authentication/api-key/main.tsp， but there's no isUnexpected helper getting generated. Refer to : https://github.com/Azure/autorest.typescript/pull/2936#discussion_r1908118552
There's error model defined in https://github.com/microsoft/typespec/blob/main/packages/http-specs/specs/authentication/api-key/main.tsp， but there's no isUnexpected helper getting generated. Refer to : #2936 (comment)