The "DefaultApi.java" class and the "JsonUtil.java" class of an Android Client SDK generated from a swagger definition without a "definitions" section, has an import statement
"import org.wso2.client.model.
2.2.2 , 2.2.3
Below is a screenshot of the Android Client SDK

@vlgunarathne as a workaround, I wonder if you can try generating the Java API client, which is also compatible with Android: https://github.com/swagger-api/swagger-codegen/wiki/FAQ#how-can-i-generate-an-android-sdk
@wing328, Got it working with the Java API client. Thanks for the workaround!
@vlgunarathne glad to hear that. Closing this one as I remember there's another issue to track something similar.