def can_copy():
fd1 = FrozenDict({1: 2, 3: 4})
fd2 = fd1.copy()
assert isinstance(fd2, FrozenDict)
assert fd2 == fd1
assert hash(fd2) == hash(fd1)
assert fd2 is not fd1
fd3 = copy(fd1)
assert isinstance(fd3, FrozenDict)
assert fd3 == fd1
assert hash(fd3) == hash(fd1)
assert fd3 is not fd1
def can_read():
fd = FrozenDict({1: 2, 3: 4})
assert fd == {1: 2, 3: 4}
assert list(i for i in fd) == [1, 3]
assert fd.copy() == fd
assert 3 in fd
assert 2 not in fd
assert fd[1] == 2
with raises(KeyError):
fd[2]
assert len(fd) == 2
assert fd.get(1) == 2
assert fd.get(2, 5) == 5
assert list(fd.items()) == [(1, 2), (3, 4)]
assert list(fd.keys()) == [1, 3]
assert list(fd.values()) == [2, 4]