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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 create(cls, name, size, type, quantity, duration, datacenter, vhosts, password, snapshot_profile, background, sshkey):
 """Create a new PaaS instance."""

        if not background and not cls.intty():
            background = True

        datacenter_id_ = int(Datacenter.usable_id(datacenter))

        paas_params = {
            'name': name,
            'size': size,
            'type': type,
            'duration': duration,
            'datacenter_id': datacenter_id_,
        }

        if password:
            paas_params['password'] = password

        if quantity:
            paas_params['quantity'] = quantity

        paas_params.update(cls.convert_sshkey(sshkey))

        if snapshot_profile:
            paas_params['snapshot_profile'] = snapshot_profile

        result = cls.call('paas.create', paas_params)

        if not background:
            # interactive mode, run a progress bar
            cls.echo('Creating your PaaS instance.')
            cls.display_progress(result)
            cls.echo('Your PaaS instance %s has been created.' % name)

        if vhosts:
            paas_info = cls.info(name)
            Vhost.create(paas_info, vhosts, True, background)

        return result