OptionParser            A function to create an istance of the class
                        OptionParser.
OptionParser-class      Class "OptionParser"
OptionParserOption-class
                        Class "OptionParserOption"
add_option              Functions to enable our OptionParser to
                        recognize specific command line options.
optparse-package        Command line option parser
parse_args              Parse command line options.
print_help              Printing an usage message from an OptionParser
                        object
