code: public static <K, V> ScanIterator<K> scan(RedisKeyCommands<K, V> commands, ScanArgs scanArgs) {
  
          LettuceAssert.notNull(scanArgs, "ScanArgs must not be null");
  
          return scan(commands, Optional.of(scanArgs));
      }
docs: Sequentially iterate over keys in the keyspace. This method uses {@code SCAN} to perform an iterative scan.
  
  @param commands the commands interface, must not be {@literal null}.
  @param scanArgs the scan arguments, must not be {@literal null}.
  @param <K> Key type.
  @param <V> Value type.
  @return a new {@link ScanIterator}.