private static void ensureBundleContains(Bundle args, String key) {
        if (args.containsKey(key)) return;
        throw new IllegalArgumentException("Bundle must contain " + key);
    }
Gets the {@link ComponentName} of the connected Trusted Web Activity client app.
@return The Trusted Web Activity client app component name.
customtabs/src/android/support/customtabs/trusted/TrustedWebActivityServiceWrapper.java