ScreenTagHistory { public String getTag() { return tag != null ? tag : ""; } ScreenTagHistory(); private  ScreenTagHistory(String fragment, String tag, String store); String getStore(); String getFragment(); void setFragment(String fragment); String getTag(); void setTag(String tag); @Override String toString();  }
@Test public void checkIfNullTagReturnEmptyStringTag() { ScreenTagHistory screenTagHistory = ScreenTagHistory.Builder.build("fragment", null, "home"); assertFalse(screenTagHistory.getTag() == null); assertTrue(screenTagHistory.getTag() .equals("")); }