Kotlin_implicit_return4.kt

fun EditText.setOnKeyboardSubmitListener(block: () -> Unit) {
    setOnEditorActionListener { _, actionId, _ ->
        if (actionId == EditorInfo.IME_ACTION_DONE) {
            block()
            true // implicit and won't do anything
            // should use return@setOnEditorActionListener
        }
        false // explicit
    }
}