+ /**
+ * Create an instance of SGSerial.
+ * This creates an instance of the SGSerial class. You need to
+ * provide the serial device name and desired baud rate. For Unix
+ * style systems, device names will be similar to
+ * ``/dev/ttyS0''. For DOS style systems you may want to use
+ * something similar to ``COM1:''. As with the SGFile class,
+ * device is not opened immediately, but instead will be opened
+ * when the open() method is called.
+ * @param device_name name of serial device
+ * @param baud_rate speed of communication
+ */