src/vs/workbench/contrib/terminal/browser/terminalTypeAheadAddon.ts/BackspacePrediction/rollback
class BackspacePrediction:	rollback(cursor: Cursor) {
		if (!this._appliedAt) {
			return ''; // not applied
		}

		const { oldAttributes, oldChar, pos } = this._appliedAt;
		if (!oldChar) {
			return cursor.moveTo(pos) + DELETE_CHAR;
		}

		return oldAttributes + oldChar + cursor.moveTo(pos) + attributesToSeq(core(this._terminal)._inputHandler._curAttrData);
	}