Complex classes like Give_Background_Updater often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Give_Background_Updater, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 21 | class Give_Background_Updater extends WP_Background_Process { | 
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| 22 | |||
| 23 | /**  | 
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| 24 | * @var string  | 
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| 25 | */  | 
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| 26 | protected $action = 'give_db_updater';  | 
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| 27 | |||
| 28 | /**  | 
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| 29 | * Dispatch updater.  | 
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| 30 | *  | 
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| 31 | * Updater will still run via cron job if this fails for any reason.  | 
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| 32 | */  | 
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| 33 | 	public function dispatch() { | 
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| 40 | |||
| 41 | |||
| 42 | /**  | 
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| 43 | * Get all batches.  | 
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| 44 | *  | 
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| 45 | * @since 2.0  | 
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| 46 | * @access public  | 
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| 47 | * @return stdClass  | 
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| 48 | */  | 
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| 49 | 	public function get_all_batch() { | 
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| 52 | |||
| 53 | /**  | 
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| 54 | * Is queue empty  | 
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| 55 | *  | 
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| 56 | * @since 2.0.3  | 
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| 57 | *  | 
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| 58 | * @return bool  | 
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| 59 | */  | 
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| 60 | 	public function has_queue() { | 
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| 63 | |||
| 64 | |||
| 65 | /**  | 
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| 66 | * Lock process  | 
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| 67 | *  | 
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| 68 | * Lock the process so that multiple instances can't run simultaneously.  | 
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| 69 | * Override if applicable, but the duration should be greater than that  | 
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| 70 | * defined in the time_exceeded() method.  | 
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| 71 | *  | 
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| 72 | *  | 
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| 73 | * @since 2.0.3  | 
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| 74 | */  | 
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| 75 | 	protected function lock_process() { | 
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| 104 | |||
| 105 | /**  | 
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| 106 | * Handle cron healthcheck  | 
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| 107 | *  | 
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| 108 | * Restart the background process if not already running  | 
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| 109 | * and data exists in the queue.  | 
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| 110 | */  | 
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| 111 | 	public function handle_cron_healthcheck() { | 
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| 126 | |||
| 127 | /**  | 
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| 128 | * Schedule fallback event.  | 
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| 129 | */  | 
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| 130 | 	protected function schedule_event() { | 
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| 135 | |||
| 136 | /**  | 
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| 137 | * Is queue empty  | 
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| 138 | *  | 
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| 139 | * @since 2.4.5  | 
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| 140 | *  | 
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| 141 | * @return bool  | 
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| 142 | */  | 
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| 143 | 	protected function is_queue_empty() { | 
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| 159 | |||
| 160 | /**  | 
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| 161 | * Get batch  | 
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| 162 | *  | 
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| 163 | * @since 2.4.5  | 
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| 164 | *  | 
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| 165 | * @return stdClass Return the first batch from the queue  | 
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| 166 | */  | 
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| 167 | 	protected function get_batch() { | 
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| 191 | |||
| 192 | /**  | 
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| 193 | * Save queue  | 
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| 194 | *  | 
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| 195 | * @since 2.4.5  | 
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| 196 | *  | 
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| 197 | * @return $this  | 
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| 198 | */  | 
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| 199 | 	public function save() { | 
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| 208 | |||
| 209 | /**  | 
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| 210 | * Update queue  | 
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| 211 | *  | 
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| 212 | * @since 2.4.5  | 
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| 213 | *  | 
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| 214 | * @param string $key Key.  | 
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| 215 | * @param array $data Data.  | 
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| 216 | *  | 
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| 217 | * @return $this  | 
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| 218 | */  | 
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| 219 | 	public function update( $key, $data ) { | 
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| 226 | |||
| 227 | /**  | 
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| 228 | * Delete queue  | 
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| 229 | *  | 
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| 230 | * @since 2.4.5  | 
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| 231 | *  | 
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| 232 | * @param string $key Key.  | 
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| 233 | *  | 
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| 234 | * @return $this  | 
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| 235 | */  | 
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| 236 | 	public function delete( $key ) { | 
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| 241 | |||
| 242 | /**  | 
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| 243 | * Is process running  | 
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| 244 | *  | 
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| 245 | * @since 2.4.5  | 
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| 246 | *  | 
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| 247 | * Check whether the current process is already running  | 
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| 248 | * in a background process.  | 
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| 249 | */  | 
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| 250 | 	public function is_process_running() { | 
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| 258 | |||
| 259 | /**  | 
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| 260 | * Unlock process  | 
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| 261 | *  | 
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| 262 | * Unlock the process so that other instances can spawn.  | 
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| 263 | *  | 
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| 264 | * @since 2.4.5  | 
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| 265 | *  | 
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| 266 | * @return $this  | 
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| 267 | */  | 
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| 268 | 	protected function unlock_process() { | 
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| 273 | |||
| 274 | /**  | 
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| 275 | * Task  | 
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| 276 | *  | 
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| 277 | * Override this method to perform any actions required on each  | 
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| 278 | * queue item. Return the modified item for further processing  | 
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| 279 | * in the next pass through. Or, return false to remove the  | 
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| 280 | * item from the queue.  | 
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| 281 | *  | 
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| 282 | * @param array $update Update info  | 
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| 283 | *  | 
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| 284 | * @return mixed  | 
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| 285 | */  | 
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| 286 | 	protected function task( $update ) { | 
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| 418 | |||
| 419 | /**  | 
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| 420 | * Complete  | 
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| 421 | *  | 
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| 422 | * Override if applicable, but ensure that the below actions are  | 
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| 423 | * performed, or, call parent::complete().  | 
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| 424 | */  | 
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| 425 | 	public function complete() { | 
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| 445 | |||
| 446 | /**  | 
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| 447 | * Get memory limit  | 
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| 448 | *  | 
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| 449 | * @return int  | 
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| 450 | */  | 
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| 451 | 	protected function get_memory_limit() { | 
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| 466 | |||
| 467 | /**  | 
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| 468 | * Maybe process queue  | 
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| 469 | *  | 
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| 470 | * Checks whether data exists within the queue and that  | 
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| 471 | * the process is not already running.  | 
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| 472 | */  | 
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| 473 | 	public function maybe_handle() { | 
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| 493 | |||
| 494 | /**  | 
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| 495 | * Handle  | 
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| 496 | *  | 
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| 497 | * Pass each queue item to the task handler, while remaining  | 
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| 498 | * within server memory and time limit constraints.  | 
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| 499 | */  | 
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| 500 | 	protected function handle() { | 
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| 544 | |||
| 545 | |||
| 546 | /**  | 
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| 547 | * Check if backgound upgrade paused or not.  | 
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| 548 | *  | 
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| 549 | * @since 2.0  | 
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| 550 | * @access public  | 
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| 551 | * @return bool  | 
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| 552 | */  | 
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| 553 | 	public function is_paused_process(){ | 
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| 561 | |||
| 562 | |||
| 563 | /**  | 
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| 564 | * Get identifier  | 
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| 565 | *  | 
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| 566 | * @since 2.0  | 
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| 567 | * @access public  | 
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| 568 | * @return mixed|string  | 
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| 569 | */  | 
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| 570 | 	public function get_identifier() { | 
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| 573 | |||
| 574 | /**  | 
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| 575 | * Get cron identifier  | 
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| 576 | *  | 
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| 577 | * @since 2.0  | 
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| 578 | * @access public  | 
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| 579 | * @return mixed|string  | 
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| 580 | */  | 
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| 581 | 	public function get_cron_identifier() { | 
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| 584 | |||
| 585 | |||
| 586 | /**  | 
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| 587 | * Flush background update related cache to prevent task to go to stalled state.  | 
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| 588 | *  | 
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| 589 | * @since 2.0.3  | 
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| 590 | */  | 
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| 591 | 	public static function flush_cache() { | 
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| 608 | }  | 
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| 609 |