How to use the imapclient.imapclient.IMAPClient function in IMAPClient

def assert_tls_already_established(self):
        with self.assertRaises(IMAPClient.AbortError) as raised:
            self.client.starttls(sentinel.ssl_context)
        self.assertEqual(str(raised.exception), "TLS session already established")

from .imapclient import IMAPClient

try:
    from unittest.mock import Mock
except ImportError:
    try:
        from mock import Mock
    except ImportError:
        raise ImportError(
            'mock library could not be loaded. Please install Python 3.3 or newer '
            'or install the `mock` third-party package through PyPi.'
        )


class TestableIMAPClient(IMAPClient):
    """Wrapper of :py:class:`imapclient.IMAPClient` that mocks all
    interaction with real IMAP server.

    This class should only be used in tests, where you can safely
    interact with imapclient without running commands on a real
    IMAP account.
    """

    def __init__(self):
        super(TestableIMAPClient, self).__init__('somehost')

    def _create_IMAP4(self):
        return MockIMAP4()


class MockIMAP4(Mock):

def test_stream(self):
        fakeIMAP4_stream = Mock()
        self.imaplib.IMAP4_stream.return_value = fakeIMAP4_stream

        imap = IMAPClient('command', stream=True, ssl=False)

        self.assertEqual(imap._imap, fakeIMAP4_stream)
        self.imaplib.IMAP4_stream.assert_called_with('command')

        self.assertEqual(imap.host, 'command')
        self.assertEqual(imap.port, None)
        self.assertEqual(imap.ssl, False)
        self.assertEqual(imap.stream, True)

def test_plain(self):
        fakeIMAP4 = Mock()
        self.imap4.IMAP4WithTimeout.return_value = fakeIMAP4

        imap = IMAPClient('1.2.3.4', ssl=False, timeout=sentinel.timeout)

        self.assertEqual(imap._imap, fakeIMAP4)
        self.imap4.IMAP4WithTimeout.assert_called_with(
            '1.2.3.4', 143,
            SocketTimeout(sentinel.timeout, sentinel.timeout)
        )
        self.assertEqual(imap.host, '1.2.3.4')
        self.assertEqual(imap.port, 143)
        self.assertEqual(imap.ssl, False)
        self.assertEqual(imap.ssl_context, None)
        self.assertEqual(imap.stream, False)

def test_SSL(self):
        fakeIMAP4_TLS = Mock()
        self.tls.IMAP4_TLS.return_value = fakeIMAP4_TLS

        imap = IMAPClient('1.2.3.4', ssl_context=sentinel.context,
                          timeout=sentinel.timeout)

        self.assertEqual(imap._imap, fakeIMAP4_TLS)
        self.tls.IMAP4_TLS.assert_called_with(
            '1.2.3.4', 993,
            sentinel.context, 
            SocketTimeout(sentinel.timeout, sentinel.timeout)
        )
        self.assertEqual(imap.host, '1.2.3.4')
        self.assertEqual(imap.port, 993)
        self.assertEqual(imap.ssl, True)
        self.assertEqual(imap.ssl_context, sentinel.context)
        self.assertEqual(imap.stream, False)

if POLL_SUPPORT:
            poll_func = self._poll_socket
        else:
            poll_func = self._select_poll_socket

        try:
            resps = []
            events = poll_func(sock, timeout)
            if events:
                while True:
                    try:
                        line = self._imap._get_line()
                    except (socket.timeout, socket.error):
                        break
                    except IMAPClient.AbortError:
                        # An imaplib.IMAP4.abort with "EOF" is raised
                        # under Python 3
                        err = sys.exc_info()[1]
                        if 'EOF' in err.args[0]:
                            break
                        else:
                            raise
                    else:
                        resps.append(_parse_untagged_response(line))
            return resps
        finally:
            sock.setblocking(1)
            self._set_read_timeout()