src/vs/editor/common/cursor/cursorMoveOperations.ts/MoveOperations/_isBlankLine
class MoveOperations:	private static _isBlankLine(model: ICursorSimpleModel, lineNumber: number): boolean {
		if (model.getLineFirstNonWhitespaceColumn(lineNumber) === 0) {
			// empty or contains only whitespace
			return true;
		}
		return false;
	}