src/vs/editor/contrib/linesOperations/copyLinesCommand.ts/CopyLinesCommand/computeCursorState
class CopyLinesCommand:	public computeCursorState(model: ITextModel, helper: ICursorStateComputerData): Selection {
		let result = helper.getTrackedSelection(this._selectionId!);

		if (this._startLineNumberDelta !== 0 || this._endLineNumberDelta !== 0) {
			let startLineNumber = result.startLineNumber;
			let startColumn = result.startColumn;
			let endLineNumber = result.endLineNumber;
			let endColumn = result.endColumn;

			if (this._startLineNumberDelta !== 0) {
				startLineNumber = startLineNumber + this._startLineNumberDelta;
				startColumn = 1;
			}

			if (this._endLineNumberDelta !== 0) {
				endLineNumber = endLineNumber + this._endLineNumberDelta;
				endColumn = 1;
			}

			result = Selection.createWithDirection(startLineNumber, startColumn, endLineNumber, endColumn, this._selectionDirection);
		}

		return result;
	}