def load(self, filename, create_if_missing=True):
        filename = Path(filename)
        if not filename.exists() and create_if_missing:
            self.load_pip_requirements()
            with filename.open("w") as f:
                f.write(yaml.dump(self.serialized, default_flow_style=False,
                                  encoding=None))
            self.filename = filename
            return self.save(filename)
        with filename.open() as f:
            for group, requirements in yaml.load(f.read()).items():
                for requirement in requirements:
                    self[group].add(Requirement.coerce(requirement))
        self.filename = filename
def test():
    start = time.time()
    treap = None
    s = set()
    for i in range(100000):
        key = random.randint(0, 10000)
        if random.randint(0, 1) == 0:
            if key in s:
                treap = remove(treap, key)
                s.remove(key)
        elif key not in s:
            treap = insert(treap, key)
            s.add(key)
        assert len(s) == size(treap)

    for i in range(size(treap)):
        assert kth(treap, i) in s
    print(time.time() - start)