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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_serial_port():
 """ Return serial.Serial instance, ready to use for RS485."""

    port = Serial(port='/dev/ttyS1', baudrate=9600, parity=PARITY_NONE,
                  stopbits=1, bytesize=8, timeout=1)

    fh = port.fileno()

    # A struct with configuration for serial port.
    serial_rs485 = struct.pack('hhhhhhhh', 1, 0, 0, 0, 0, 0, 0, 0)
    fcntl.ioctl(fh, 0x542F, serial_rs485)

    return port