def _update_cache_stats(self, key, result):
if result is None:<EOL><INDENT>self._CACHE_STATS['<STR_LIT>'].setdefault(key,<EOL>{'<STR_LIT>': <NUM_LIT:0>, '<STR_LIT>': <NUM_LIT:0>, '<STR_LIT>': <NUM_LIT:0>})<EOL><DEDENT>else:<EOL><INDENT>self._CACHE_STATS['<STR_LIT>'][key][result] +=<NUM_LIT:1><EOL><DEDENT>
Update the cache stats.

If no cache-result is specified, we iniitialize the key.
Otherwise, we increment the correct cache-result.

Note the behavior for expired.  A client can be expired and the key
still exists.