def __init__(self, initial_cache=None):
        """
        >>> c = LRUCache()
        >>> c.stats()['size']
        0
        >>> c['key1'] = 'value1'
        >>> c.keys()
        ['key1']
        >>> c['key1']
        'value1'
        >>> del c['key1']
        """
        self._cache = initial_cache or {}
        self._size = 0
        self._hits = 0
        self._misses = 0
        self._order = dllist.DLL()
def __init__ ( self , initial_cache = None ) : self . _cache = initial_cache or { } self . _size = 0 self . _hits = 0 self . _misses = 0 self . _order = dllist . DLL ( )
>>> c = LRUCache()
        >>> c.stats()['size']
        0
        >>> c['key1'] = 'value1'
        >>> c.keys()
        ['key1']
        >>> c['key1']
        'value1'
        >>> del c['key1']