src/vs/editor/browser/viewParts/currentLineHighlight/currentLineHighlight.ts/AbstractLineHighlightOverlay/_readFromSelections
class AbstractLineHighlightOverlay:	private _readFromSelections(): boolean {
		let hasChanged = false;

		const cursorsLineNumbers = this._selections.map(s => s.positionLineNumber);
		cursorsLineNumbers.sort((a, b) => a - b);
		if (!arrays.equals(this._cursorLineNumbers, cursorsLineNumbers)) {
			this._cursorLineNumbers = cursorsLineNumbers;
			hasChanged = true;
		}

		const selectionIsEmpty = this._selections.every(s => s.isEmpty());
		if (this._selectionIsEmpty !== selectionIsEmpty) {
			this._selectionIsEmpty = selectionIsEmpty;
			hasChanged = true;
		}

		return hasChanged;
	}