src/vs/editor/common/cursor/cursor.ts/CursorsController/getCursorColumnSelectData
class CursorsController:	public getCursorColumnSelectData(): IColumnSelectData {
		if (this._columnSelectData) {
			return this._columnSelectData;
		}
		const primaryCursor = this._cursors.getPrimaryCursor();
		const viewSelectionStart = primaryCursor.viewState.selectionStart.getStartPosition();
		const viewPosition = primaryCursor.viewState.position;
		return {
			isReal: false,
			fromViewLineNumber: viewSelectionStart.lineNumber,
			fromViewVisualColumn: this.context.cursorConfig.visibleColumnFromColumn(this._viewModel, viewSelectionStart),
			toViewLineNumber: viewPosition.lineNumber,
			toViewVisualColumn: this.context.cursorConfig.visibleColumnFromColumn(this._viewModel, viewPosition),
		};
	}