'Return the number of device groups in the specified copy group.'

def _check_copy_grp(self, copy_group):

    count = 0
    result = self.run_raidcom('get', 'copy_grp')
    for line in result[1].splitlines()[1:]:
        line = line.split()
        if (line[0] == copy_group):
            count += 1
            if (count == 2):
                break
    return count
