def send_command(self, command):
        """Sends command to guest VM and returns it's output.

        :param command: String containing desired commmand.
        :returns: Command's output inside VM.
        """
        if not self._is_running:
            return None

        self._proc.sendline(command)
        self._proc.expect(self._prompt)
        return self._proc.before
Sends command to guest VM and returns it's output.

        :param command: String containing desired commmand.
        :returns: Command's output inside VM.
        
lisa/core/qemu_guest.py