Method safeString

java/lib/src/main/java/io/github/ccxt/Exchange.java:987–989

(Object obj, Object key, Object... defaultValue)

    // SafeString / SafeStringN
    public Object safeString(Object obj, Object key, Object... defaultValue) {
        return SafeMethods.SafeString(obj, key, defaultValue);
    }

    public Object safeString2(Object obj, Object key1, Object key2, Object... defaultValue) {
        return SafeMethods.safeString2(obj, key1, key2, defaultValue);