static fromRangeMappings(rangeMappings) {
        const originalRange = LineRange.join(rangeMappings.map(r => LineRange.fromRangeInclusive(r.originalRange)));
        const modifiedRange = LineRange.join(rangeMappings.map(r => LineRange.fromRangeInclusive(r.modifiedRange)));
        return new DetailedLineRangeMapping(originalRange, modifiedRange, rangeMappings);
    }
Maps a line range in the original text model to a line range in the modified text model.
Also contains inner range mappings.