Unable to use Patch using patchNamespacedDeployment client-java-1.0.0-beta3-SNAPSHOT.jar of Kubernetes

Description

Patch operation fails when passing this structure as body:
static String PatchStr = "{\"spec\":{\"template\":{\"spec\":{\"containers\":[{\"name\":\"containername\",\"image\":\"xxx/xxx/xxx-xxx:3.0.1.45\"}]}}}}"; .My requirement is to update the container based on its image value.

Getting this error:
PATCH https://xx.xx.xx.xxx/apis/extensions/v1beta1/namespaces/default/deployments/xxx?pretty=false HTTP/1.1
Content-Type: application/json-patch+json; charset=utf-8
Content-Length: 124
authorization: Token xxxxxxxxxxxxxxxxxxxxxxxxxxx
Accept: application/json
User-Agent: Swagger-Codegen/1.0-SNAPSHOT/java

[{"spec":{"template":{"spec":{"containers":[{"name":"containername","image":"xxx/xxxxxxx/xxx-app:3.0.1.45"}]}}}}]
--> END PATCH (124-byte body)
<-- HTTP/1.1 500 Internal Server Error (1257ms)
Content-Type: application/json
Date: Fri, 30 Mar 2018 08:12:57 GMT
Content-Length: 117
OkHttp-Sent-Millis: 1522397577354
OkHttp-Received-Millis: 1522397577559

{"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"Unexpected kind: unknown","code":500}

<-- END HTTP (117-byte body)
Exception in thread "main" io.kubernetes.client.ApiException: Internal Server Error
at io.kubernetes.client.ApiClient.handleResponse(ApiClient.java:882)
at io.kubernetes.client.ApiClient.execute(ApiClient.java:798)
at io.kubernetes.client.apis.ExtensionsV1beta1Api.patchNamespacedDeploymentWithHttpInfo(ExtensionsV1beta1Api.java:5617)
at io.kubernetes.client.apis.ExtensionsV1beta1Api.patchNamespacedDeployment(ExtensionsV1beta1Api.java:5600)
at io.kubernetes.client.examples.UpdateExample.main(UpdateExample.java:76)

Swagger-codegen version

Swagger declaration file content or url

Command line used for generation

Steps to reproduce

Related issues/PRs

Suggest a fix/enhancement

Start with UpdateExample.java at line 76, then trace the call through ExtensionsV1beta1Api.patchNamespacedDeployment and ApiClient.handleResponse. Reproduce the request using the shown patch body and inspect why the Kubernetes API returns "Unexpected kind: unknown"; done means the generated client sends a valid patch and the deployment update succeeds.