MainActivity.kt

 private fun postNewGroceryItemToServer(dialog: DialogInterface, view: View) {
        val etItemName = view.findViewById<EditText>(R.id.et_grocery_item_name)
        val checkBoxIsAvailable = view.findViewById<CheckBox>(R.id.checkbox_grocery_item_is_available)
        val groceryItem = GroceryItem(etItemName.text.toString(), checkBoxIsAvailable.isChecked)

        swipe_refresh_grocery_items.isRefreshing = true

        GroceryServiceFactory.makeService().addGroceryItem(groceryItem).enqueue(object: Callback<StatusResponseEntity<GroceryItem>?> {
            override fun onFailure(call: Call<StatusResponseEntity<GroceryItem>?>, t: Throwable) {
                swipe_refresh_grocery_items.isRefreshing = false
                Toast.makeText(this@MainActivity, "Oops something went wrong please check your internet connection", Toast.LENGTH_LONG).show()
            }

            override fun onResponse(
                call: Call<StatusResponseEntity<GroceryItem>?>,
                response: Response<StatusResponseEntity<GroceryItem>?>
            ) {
                swipe_refresh_grocery_items.isRefreshing = false
                if (response.body() != null && response.body()?.status == true) { // our business rule is that if status is true then entity is not null
                    groceryItemAdapter.add(response.body()!!.entity!!)
                } else {
                    Toast.makeText(this@MainActivity, "Something went terribly wrong", Toast.LENGTH_LONG).show()
                }
            }
        })
        dialog.dismiss()
    }