loss of key after pickle.loads

[maybe-why-not]

import pybloomfilter
fruit = pybloomfilter.BloomFilter(100000, 0.1, '/tmp/words.bloom')
fruit.update(('apple', 'pear', 'orange', 'apple'))
print(len(fruit))
print('mike' in fruit)
print('apple' in fruit)

import pickle
pickled_fruit = pickle.dumps(fruit)
unpickled_fruit = pickle.loads(pickled_fruit)
print('apple' in unpickled_fruit)

print('apple' in unpickled_fruit) is False