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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_credentials(options, environment):
 """ Get credentials or prompt for them from options """

    if options['--username'] or options['--auth']:
        if not options['--username']:
            options['<username>'] = lib.prompt("Please enter the username for %s..." % environment)
        if not options['--password']:
            options['<password>'] = lib.prompt("Please enter the password for %s..." % environment, secret=True)
    return options