>>> from botigaroba import incrementa_estoc

>>> d = {('Pan85', 'XS','negre'):100,('Pan85','S','negre'):300,
... ('Pan85','XS','blau'):6,('Pan87','S','blau'):5,
... ('Pan87','L','blau'):12}
>>> incrementa_estoc(d,'Pan85','S','negre',10)
>>> d == {('Pan85', 'XS','negre'):100,('Pan85','S','negre'):310,
... ('Pan85','XS','blau'):6,('Pan87','S','blau'):5,
... ('Pan87','L','blau'):12}
True
>>> incrementa_estoc(d,'Pan85','M','negre',10)
>>> d == {('Pan85', 'XS','negre'):100,('Pan85','S','negre'):310,
... ('Pan85','XS','blau'):6,('Pan87','S','blau'):5,
... ('Pan87','L','blau'):12,('Pan85','M','negre'):10}
True