>>> from mestrams import mes_llarga_tram

--ini-enunciat
>>> it = iter('ocell pardal flor amic llum i arbre paravent adeu darrer'.split())
>>> it2 = mes_llarga_tram(it, 7)
>>> iter(it2) == it2
True
>>> next(it2)
'pardal'
>>> next(it2)
'paravent'
>>> next(it2, 'iterador exhaurit')
'iterador exhaurit'

>>> it = iter('ocell pardal flor amic llum i arbre paravent adeu darrer'.split())
>>> it2 = mes_llarga_tram(it, 12)
>>> next(it2)
'paravent'
>>> next(it2, 'iterador exhaurit')
'iterador exhaurit'

--fi-enunciat

>>> it = iter('ocell pardal flor amic llum i arbre paravent adeu darrer'.split())
>>> it2 = mes_llarga_tram(it, 5)
>>> list(it2)
['pardal', 'paravent']

>>> it = iter('ocell pardal flor amic llum i arbre paravent adeu darrer'.split())
>>> it2 = mes_llarga_tram(it, 15)
>>> list(it2)
['paravent']

>>> it = iter('ocell pardal flor amic llum i arbre paravent adeu darrer'.split())
>>> it2 = mes_llarga_tram(it, 1)
>>> list(it2) == 'ocell pardal flor amic llum i arbre paravent adeu darrer'.split()
True
>>> it = iter('hola carambola gosol MOL foll pol pollastre col i potatoes'.split())
>>> iter(it2) == it2
True
>>> it2 = mes_llarga_tram(it,  5)
>>> next(it2)
'carambola'
>>> next(it2)
'pollastre'
>>> next(it2, 'stop')
'stop'


>>> it = iter('hola carambola gosol MOL foll pol pollastre col i caramels'.split())
>>> it2 = mes_llarga_tram(it, 2)
>>> list(it2)
['carambola', 'gosol', 'foll', 'pollastre', 'caramels']

>>> it = iter('hola carambola gosol MOL foll pol pollastre col i patates'.split())
>>> it2 = mes_llarga_tram(it,  100)
>>> list(it2)
['carambola']

>>> it = iter('hola carambola gosol amanida foll pol endivia col i patates'.split())
>>> it2 = mes_llarga_tram(it,  3)
>>> list(it2)
['carambola', 'amanida', 'endivia', 'patates']