error catching decorator for retrofit instance

ErrorApiDecorator.kt

import rx.Observable
import rx.Single
import java.lang.reflect.InvocationHandler
import java.lang.reflect.Method
import java.lang.reflect.Proxy

/**
 * Created by punksta on 18.10.16.
 */
object ErrorApiDecorator : IApiDecorator {
    override fun <T : I, I> decorate(api: T, clazz: Class<I>): I {
        return decorateErrors(api, clazz)
    }

    fun <T : I, I> decorateErrors(api: T, clazz: Class<I>): I {
        val handler: InvocationHandler = InvocationHandler { any: Any?, method: Method, arrayOfAny: Array<out Any>? ->
            method.invoke(api, *arrayOfAny.orEmpty())
                    .let {
                        when (it) {
                            is Single<*> -> it.doOnError {
                                RxEventBus.postEvent(it)
                            }
                            is Observable<*> -> it.doOnError {
                                RxEventBus.postEvent(it)
                            }
                            else -> it
                        }
                    }
        }

        val proxy = Proxy.newProxyInstance(clazz.classLoader, arrayOf(clazz), handler)
        return proxy as I
    }
}