How to avoid memory leaks due to custom static handler class?

I have certain memory leaks happening in my custom handler class ,but not sure how to fix it. checkedout a couple of examples online but nothing is specific to my code so not sure how to go about it :

private val startupCallback = object: RetryCallback(NUMBER, DELAY) {
        override fun onRetry(retryCount: Int) {

            mySdkApi.applicationStartup(this)
        }

        override fun onCompleted(): Boolean {
            updateStatus(Callback.Status.StartUpSDK)

            return true
        }

        override fun onFailed(e: MyException?) {
            updateStatus(Callback.Status.StartUpSDK, "", e)
        }
    }

Android studio keeps prompting "This handler class should be static or leaks might occur".Any ideas how to go about it?

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