def _inner_change(self, value):
data, version = self._value()
# Decrement counter only if data(current count) is non zero.
if data > 0 or value > 0:
data += value
# Dont raise OverQuota during delete
if (data > self.max_count and value > 0):
raise OverQuota()
try:
self.client.set(
self.path, repr(data).encode('ascii'), version=version)
except kazoo.exceptions.BadVersionError: # pragma: nocover
raise ForceRetryError()