code: def invalidate(self, key):
          '''Clear an item from the cache'''
          path = self.path(self.xform_key(key))
          try:
              LOG.debug('invalidate %s (%s)', key, path)
              path.unlink()
          except OSError:
              pasf invalidate(self, key):
          '''Clear an item from the cache'''
          path = self.path(self.xform_key(key))
          try:
              LOG.debug('invalidate %s (%s)', key, path)
              path.unlink()
          except OSError:
              pass
docs: Clear an item from the cache