src/vs/editor/common/viewModel/viewModelLines.ts/ViewModelLinesFromProjectedModel/getActiveIndentGuide
class ViewModelLinesFromProjectedModel:	public getActiveIndentGuide(viewLineNumber: number, minLineNumber: number, maxLineNumber: number): IActiveIndentGuideInfo {
		viewLineNumber = this._toValidViewLineNumber(viewLineNumber);
		minLineNumber = this._toValidViewLineNumber(minLineNumber);
		maxLineNumber = this._toValidViewLineNumber(maxLineNumber);

		const modelPosition = this.convertViewPositionToModelPosition(viewLineNumber, this.getViewLineMinColumn(viewLineNumber));
		const modelMinPosition = this.convertViewPositionToModelPosition(minLineNumber, this.getViewLineMinColumn(minLineNumber));
		const modelMaxPosition = this.convertViewPositionToModelPosition(maxLineNumber, this.getViewLineMinColumn(maxLineNumber));
		const result = this.model.guides.getActiveIndentGuide(modelPosition.lineNumber, modelMinPosition.lineNumber, modelMaxPosition.lineNumber);

		const viewStartPosition = this.convertModelPositionToViewPosition(result.startLineNumber, 1);
		const viewEndPosition = this.convertModelPositionToViewPosition(result.endLineNumber, this.model.getLineMaxColumn(result.endLineNumber));
		return {
			startLineNumber: viewStartPosition.lineNumber,
			endLineNumber: viewEndPosition.lineNumber,
			indent: result.indent
		};
	}