>>> from clotheshop import stock_increase

>>> d = {('Pan85', 'XS','black'):100,('Pan85','S','black'):300,
... ('Pan85','XS','blue'):6,('Pan87','S','blue'):5,
... ('Pan87','L','blue'):12}
>>> stock_increase(d,'Pan85','S','black',10)
>>> if d != {('Pan85', 'XS','black'):100,('Pan85','S','black'):310,
... ('Pan85','XS','blue'):6,('Pan87','S','blue'):5,
... ('Pan87','L','blue'):12}:
...    print(d)
>>> stock_increase(d,'Pan85','M','black',10)
>>> if d != {('Pan85', 'XS','black'):100,('Pan85','S','black'):310,
... ('Pan85','XS','blue'):6,('Pan87','S','blue'):5,
... ('Pan87','L','blue'):12,('Pan85','M','black'):10}:
...    print(d)