### Question:
Mapbox { static boolean isAccessTokenValid(@Nullable String accessToken) { if (accessToken == null) { return false; } accessToken = accessToken.trim().toLowerCase(MapboxConstants.MAPBOX_LOCALE); return accessToken.length() != 0 && (accessToken.startsWith("pk.") || accessToken.startsWith("sk.")); } Mapbox(@NonNull Context context, @Nullable String accessToken); @UiThread @NonNull static synchronized Mapbox getInstance(@NonNull Context context, @Nullable String accessToken); @Nullable static String getAccessToken(); static void setAccessToken(String accessToken); static String getSkuToken(); @NonNull static Context getApplicationContext(); static synchronized void setConnected(Boolean connected); static synchronized Boolean isConnected(); @Nullable static TelemetryDefinition getTelemetry(); @NonNull static ModuleProvider getModuleProvider(); static boolean hasInstance();  }### Answer:
@Test public void testPkTokenValid() { assertTrue(Mapbox.isAccessTokenValid("pk.0000000001")); }
@Test public void testSkTokenValid() { assertTrue(Mapbox.isAccessTokenValid("sk.0000000001")); }
@Test public void testEmptyToken() { assertFalse(Mapbox.isAccessTokenValid("")); }
@Test public void testNullToken() { assertFalse(Mapbox.isAccessTokenValid(null)); }
@Test public void testBlaBlaToken() { assertFalse(Mapbox.isAccessTokenValid("blabla")); }