presto-main/src/main/java/io/prestosql/type/CharOperators.java/CharOperators/xxHash64
class CharOperators:    @LiteralParameters("x")
    @ScalarOperator(XX_HASH_64)
    @SqlType(StandardTypes.BIGINT)
    public static long xxHash64(@SqlType("char(x)") Slice slice)
    {
        return XxHash64.hash(slice);
    }