def fifo_for_evict(cache_dict, evict_number=<NUM_LIT:1>):
ordered_dict = sorted(cache_dict.items(), key=lambda t: t[<NUM_LIT:1>]['<STR_LIT>'])<EOL>evicted_keys = []<EOL>if len(cache_dict) < evict_number:<EOL><INDENT>evict_number = len(cache_dict)<EOL><DEDENT>for i in range(evict_number):<EOL><INDENT>item = ordered_dict[i]<EOL>key = item[<NUM_LIT:0>]<EOL>cache_dict.pop(key)<EOL>evicted_keys.append(key)<EOL><DEDENT>return evicted_keys<EOL>
Use FIFO(First In First Out) strategy for evicting, it will find an item by earliest birthday date then remove it.

Test:
>>> from common_cache import CacheItem
>>> dict = {}
>>> dict['a'] = CacheItem(key='a', value=0, expire=5)
>>> dict['b'] = CacheItem(key='b', value=1, expire=5)
>>> dict['c'] = CacheItem(key='c', value=2, expire=5)
>>> len(dict)
3
>>> evicted_keys = fifo_for_evict(dict, evict_number=2)
>>> len(dict)
1
>>> len(evicted_keys)
2
>>> evicted_keys
['a', 'b']
>>> evicted_keys = fifo_for_evict(dict, evict_number=10)
>>> len(dict)
0
>>> len(evicted_keys)
1