static const unsigned char head[] = {44, 33, 22, 11};
static const unsigned char tail[] = {11, 22, 33, 44};
static const unsigned char freed[] = {99, 99, 99, 99};
static const unsigned char head[] = {44, 33, 22, 11};
static const unsigned char tail[] = {11, 22, 33, 44};
static const unsigned char freed[] = {99, 99, 99, 99};