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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 _migrate(data: Mapping[str, Any]) -> SettingsData: """ Check the version integer of the JSON file data a run any necessary migrations to get us to the latest file format. Returns dictionary of settings and version migrated to """

    next = dict(data)
    version = next.pop('_version', 0)
    target_version = len(_MIGRATIONS)
    migrations = _MIGRATIONS[version:]

    if len(migrations) > 0:
        log.info(
            "Migrating advanced settings from version {} to {}"
            .format(version, target_version))

    for m in migrations:
        next = m(next)

    return next, target_version