When to combine several test cases inside one test suite?

In which cases should I combine several test cases inside one test suite?

Let me give you some examples.

Example 1

I have utils.py file that contains several non-related general-purpose functions like dict_join and split_first_n. Should I create one test case for both of them and define two methods that checks each of these functions? Also should I create separate functions to test each set of parameters (e.g. expected and unexpected ones -- None, -1 etc).

class TestUtils(unittest.TestCase):
    def test_dict_join(self):
        pass

    def test_split_first_n(self):
        pass

Example 2

I have TCPSocket wrapper around the Socket object from the Python's standard library with functions like recv_bytes and recv_until. Should I create one test case for this class with the methods for each of its functions that I want to test?

class TestTCPSocket(unittest.TestCase):
    def setUp(self):
        self.sock = TCPSocket()
        self.sock.connect('127.0.0.1', 12345)

    def test_recv_bytes(self):
        pass

    def test_recv_until(self):
        pass

Am I right?