my_lo_lseek
error = my_lo_lseek(xc, fd, 0, SEEK_END, &off);
error = my_lo_lseek(xc, fd, offset, SEEK_SET, NULL);
error = my_lo_lseek(xc, fd, offset, SEEK_SET, NULL);
error = my_lo_lseek(xc, fd, 0, SEEK_END, &size);
int my_lo_lseek(struct Xconn *, int32_t, int32_t, int32_t, int32_t *);