'Initialize a DNS cache.
@param max_size: The maximum number of nodes to cache; the default is 100000.  Must be > 1.
@type max_size: int'

def __init__(self, max_size=100000):

    self.data = {}
    self.set_max_size(max_size)
    self.sentinel = LRUCacheNode(None, None)
    self.lock = _threading.Lock()
