public static void startActivityFinder(final Context context, final String userName) {
        if (!checkNonBlankUsername(context, userName)) {
            return;
        }
        final Intent cachesIntent = new Intent(context, CacheListActivity.class);
        Intents.putListType(cachesIntent, CacheListType.FINDER);
        cachesIntent.putExtra(Intents.EXTRA_USERNAME, userName);
        context.startActivity(cachesIntent);
    }
Check if a given username is valid (non blank), and show a toast if it isn't.

@param context  an activity
@param username the username to check
@return <tt>true</tt> if the username is not blank, <tt>false</tt> otherwise
main/src/main/java/cgeo/geocaching/CacheListActivity.java