def METHOD_NAME(self):
    """Actual stress function."""
    # generate some random data
    data = bytes(random.getrandbits(8) for _ in range(1024))
    hasher = hashlib.sha256()
    hasher.update(data)
    while True:
        new_digest = hasher.digest()
        # use the newly obtained digest as the new data to the hasher
        hasher.update(new_digest)