def METHOD_NAME(stream, requests_mock):
    # No results
    requests_mock.get("https://dummy", json={"TotalResults": 0, "CollectionField": []})
    resp = requests.get("https://dummy")
    expected_next_page_token = None
    assert stream.next_page_token(resp) == expected_next_page_token
    # Invalid response
    requests_mock.get("https://dummy", json={"TotalResults": 1000, "CollectionField": []})
    resp = requests.get("https://dummy")
    expected_next_page_token = None
    assert stream.next_page_token(resp) == expected_next_page_token
    # Implicit page size
    requests_mock.get("https://dummy", json={"TotalResults": 1000, "CollectionField": [None, None, None]})
    resp = requests.get("https://dummy")
    expected_next_page_token = {"pgsiz": 3, "pgnum": 2}
    assert stream.next_page_token(resp) == expected_next_page_token