How to use the moler.cmd.unix.ssh.Ssh function in moler

def test_calling_ssh_returns_result_parsed_from_command_output(buffer_connection, command_output_and_expected_result):
    command_output = command_output_and_expected_result
    buffer_connection.remote_inject_response([command_output])

    ssh_cmd = Ssh(connection=buffer_connection.moler_connection, login="user", password="english",
                  host="host.domain.net", expected_prompt="host:.*#", options=None)
    assert "TERM=xterm-mono ssh -l user host.domain.net" == ssh_cmd.command_string
    assert ssh_cmd() is not None

def test_ssh_failed_known_hosts(buffer_connection, command_output_failed_known_hosts):
    command_output = command_output_failed_known_hosts
    buffer_connection.remote_inject_response([command_output])

    ssh_cmd = Ssh(connection=buffer_connection.moler_connection, login="user", password="english", prompt="client:~ #",
                  host="host.domain.net", expected_prompt="host:.*#", known_hosts_on_failure='badvalue',
                  options=None)
    assert "TERM=xterm-mono ssh -l user host.domain.net" == ssh_cmd.command_string
    with pytest.raises(CommandFailure):
        ssh_cmd()

def test_ssh_returns_proper_command_string(buffer_connection):
    ssh_cmd = Ssh(buffer_connection, login="user", password="english",
                  host="host.domain.net", expected_prompt="host:.*#", options=None)
    assert "TERM=xterm-mono ssh -l user host.domain.net" == ssh_cmd.command_string

def test_ssh_failed_host_key_verification(buffer_connection, command_output_failed_host_key_verification):
    command_output = command_output_failed_host_key_verification
    buffer_connection.remote_inject_response([command_output])

    ssh_cmd = Ssh(connection=buffer_connection.moler_connection, login="user", password="english",
                  host="host.domain.net", expected_prompt="server:.*#", prompt="host:~ #", options=None)
    assert "TERM=xterm-mono ssh -l user host.domain.net" == ssh_cmd.command_string
    with pytest.raises(CommandFailure):
        ssh_cmd()

def push_yes_if_needed(self, line):
        if (not self._sent_continue_connecting) and self._regex_helper.search_compiled(Ssh._re_yes_no, line):
            self.connection.send('yes')
            self._sent_continue_connecting = True

def is_password_requested(self, line):
        return self._regex_helper.search_compiled(Ssh._re_password, line)

def is_failure_indication(self, line):
        return self._regex_helper.search_compiled(Ssh._re_failed_strings, line)

def _get_hosts_file_if_displayed(self, line):
        """
        Checks if line from device has info about hosts file.

        :param line: Line from device.
        :return: Nothing but raises ParsingDone if regex matches.
        """
        if (self.known_hosts_on_failure is not None) and self._regex_helper.search_compiled(Ssh._re_host_key, line):
            self._hosts_file = self._regex_helper.group("HOSTS_FILE")
            raise ParsingDone()

def is_failure_indication(self, line):
        """
        Detects fail from command output.

        :param line: Line from device
        :return: Match object if matches, None otherwise
        """
        return self._regex_helper.search_compiled(Ssh._re_failed_strings, line)

def _id_dsa(self, line):
        """
        Checks id dsa.

        :param line: Line from device.
        :return: Nothing but raises ParsingDone if regex matches.
        """
        if Ssh._re_id_dsa.search(line):
            self.connection.sendline("")
            raise ParsingDone()