require valid checksum at https://github.com/qoomon/banking-swift-messages-java/blob/f066de5066ec9f580c3ff5e04f2bf26bd9ca5e6f/src/main/java/com/qoomon/banking/swift/message/block/UserTrailerBlock.java#L55 https://www.quickprogrammingtips.com/java/how-to-calculate-crc32-checksum-in-java.html
