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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 extra_info(port):
 """Collects the serial nunber and manufacturer into a string, if the fields are available."""

    extra_items = []
    if port.manufacturer:
        extra_items.append("vendor '{}'".format(port.manufacturer))
    if port.serial_number:
        extra_items.append("serial '{}'".format(port.serial_number))
    if port.interface:
        extra_items.append("intf '{}'".format(port.interface))
    if extra_items:
        return ' with ' + ' '.join(extra_items)
    return ''