Read the code carefully

import weakref
import gc


class Doc:
    def __init__(self, name):
        self.name = name


cache: weakref.WeakValueDictionary = weakref.WeakValueDictionary()
d = Doc("alpha")
cache["alpha"] = d

print("alpha" in cache)
print(cache["alpha"].name)
print(len(cache))

del d
gc.collect()

print("alpha" in cache)
print(len(cache))

What will the program print? Write here: