>>> from phone import consecutive_numbers

>>> v1 = ['934780245', '012', '618776611', '972399700', '11811',
...    '972399700', '012', '938765454', '012', '11811', '012', '11811']
>>> with open ('calls1.txt', 'w') as f:
...    for e in v1:
...        a = f.write (e + '\n')
>>> consecutive_numbers('calls1.txt')
False

>>> v2 = ['934780245', '012', '618776611', '972399700', '11811',
...     '938765454', '11811', '11811', '012', '11811']
>>> with open ('calls2.txt', 'w') as f:
...    for e in v2:
...        a = f.write (e + '\n')
>>> consecutive_numbers('calls2.txt')
True