src/vs/editor/common/viewModel/viewModelLines.ts/ViewModelLinesFromProjectedModel/onModelLinesDeleted
class ViewModelLinesFromProjectedModel:	public onModelLinesDeleted(versionId: number | null, fromLineNumber: number, toLineNumber: number): viewEvents.ViewLinesDeletedEvent | null {
		if (!versionId || versionId <= this._validModelVersionId) {
			// Here we check for versionId in case the lines were reconstructed in the meantime.
			// We don't want to apply stale change events on top of a newer read model state.
			return null;
		}

		const outputFromLineNumber = (fromLineNumber === 1 ? 1 : this.projectedModelLineLineCounts.getPrefixSum(fromLineNumber - 1) + 1);
		const outputToLineNumber = this.projectedModelLineLineCounts.getPrefixSum(toLineNumber);

		this.modelLineProjections.splice(fromLineNumber - 1, toLineNumber - fromLineNumber + 1);
		this.projectedModelLineLineCounts.removeValues(fromLineNumber - 1, toLineNumber - fromLineNumber + 1);

		return new viewEvents.ViewLinesDeletedEvent(outputFromLineNumber, outputToLineNumber);
	}