LineItem testItem = new LineItem("{\"createdTime\":1493752362963,\"taxRates\":{\"elements\":[{\"id\":\"H81CTR0MNB502\",\"isDefault\":true,\"name\":\"Broward Sales\",\"rate\":650000}]},\"userData\":null,\"alternateName\":\"\",\"id\":\"HWS8WYG986J58\",\"exchanged\":false,\"price\":1100,\"refunded\":false,\"binName\":null,\"isRevenue\":null,\"name\":\"Custom Item\",\"printed\":false,\"note\":null,\"itemCode\":null}");
boolean foo = testItem.getIsRevenue();
Log.d(TAG, "Initialization: " + foo);
generates a nullPointerException. The lineItem this was taken from was a simple custom item created in register.