code: def get(self, key):
          
          try:
              value = self._cache[key]
              self._order.push(key)
              self._hits += 1
              return value
          except KeyError, e:
              self._misses += 1
              raise
docs: >>> c = LRUCache()
          >>> c.get('toto')
          Traceback (most recent call last):
              ...
          KeyError: 'toto'
          >>> c.stats()['misses']
          1
          >>> c.put('toto', 'tata')
          >>> c.get('toto')
          'tata'
          >>> c.stats()['hits']
          1