<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def nextindx(self):
        '''
        Determine the next insert offset according to storage.

        Returns:
            int: The next insert offset.
        '''
        indx = 0
        with s_lmdbslab.Scan(self.slab, self.db) as curs:
            last_key = curs.last_key()
            if last_key is not None:
                indx = s_common.int64un(last_key) + 1
        return indx