capybara/virtualenv/lib/python2.7/site-packages/werkzeug/contrib/cache.py
def inc(self, key, delta=1):
        """Increments the value of a key by `delta`.  If the key does
        not yet exist it is initialized with `delta`.

        For supporting caches this is an atomic operation.

        :param key: the key to increment.
        :param delta: the delta to add.
        :returns: The new value or ``None`` for backend errors.
        """
        value = (self.get(key) or 0) + delta
        return value if self.set(key, value) else None
def inc(self, key, delta=1):
        """Increments the value of a key by `delta`.  If the key does
        not yet exist it is initialized with `delta`.

        For supporting caches this is an atomic operation.

        :param key: the key to increment.
        :param delta: the delta to add.
        :returns: The new value or ``None`` for backend errors.
        """
        value = (self.get(key) or 0) + delta
        return value if self.set(key, value) else None
Increments the value of a key by `delta`.  If the key does
        not yet exist it is initialized with `delta`.

        For supporting caches this is an atomic operation.

        :param key: the key to increment.
        :param delta: the delta to add.
        :returns: The new value or ``None`` for backend errors.