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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_erase_command(self, drive, pattern):
 """Return the command arguments based on the pattern. Erase command examples: 1) Sanitize: "ssacli ctrl slot=0 pd 1I:1:1 modify erase erasepattern=overwrite unrestricted=off forced" 2) Zeros: "ssacli ctrl slot=0 pd 1I:1:1 modify erase erasepattern=zero forced" :param drive: A string with comma separated list of drives. :param pattern: A string which defines the type of erase. :returns: A list of ssacli command arguments. """

        cmd_args = []
        cmd_args.append("pd %s" % drive)
        cmd_args.extend(['modify', 'erase', pattern])

        if pattern != 'erasepattern=zero':
            cmd_args.append('unrestricted=off')

        cmd_args.append('forced')
        return cmd_args