Make some functions private, because they are not useful outside

of this class. The public functions are either useful outside of
this class or useful to disable or extend using plugins

Author: Anton Evers

app/code/Magento/Cron/Observer/ProcessCronQueueObserver.php

@@ -374,7 +374,7 @@ public function generate($groupId)
      * @param   string $groupId
      * @return  $this
      */
-    public function generateJobs($jobs, $exists, $groupId)
+    private function generateJobs($jobs, $exists, $groupId)
     {
         foreach ($jobs as $jobCode => $jobConfig) {
             $cronExpression = $this->getCronExpression($jobConfig);
@@ -394,7 +394,7 @@ public function generateJobs($jobs, $exists, $groupId)
      * @param string $groupId
      * @return $this
      */
-    public function cleanup($groupId)
+    private function cleanup($groupId)
     {
         $this->cleanupDisabledJobs($groupId);
 
@@ -462,7 +462,7 @@ public function cleanup($groupId)
      * @param array $jobConfig
      * @return mixed
      */
-    public function getConfigSchedule($jobConfig)
+    private function getConfigSchedule($jobConfig)
     {
         $cronExpr = $this->scopeConfig->getValue(
             $jobConfig['config_path'],
@@ -479,7 +479,7 @@ public function getConfigSchedule($jobConfig)
      * @param array $exists
      * @return void
      */
-    public function saveSchedule($jobCode, $cronExpression, $timeInterval, $exists)
+    private function saveSchedule($jobCode, $cronExpression, $timeInterval, $exists)
     {
         $currentTime = $this->timezone->scopeTimeStamp();
         $timeAhead = $currentTime + $timeInterval;
@@ -510,7 +510,7 @@ public function saveSchedule($jobCode, $cronExpression, $timeInterval, $exists)
      * @param int $time
      * @return Schedule
      */
-    public function generateSchedule($jobCode, $cronExpression, $time)
+    private function generateSchedule($jobCode, $cronExpression, $time)
     {
         $schedule = $this->scheduleFactory->create()
             ->setCronExpr($cronExpression)
@@ -526,7 +526,7 @@ public function generateSchedule($jobCode, $cronExpression, $time)
      * @param string $groupId
      * @return int
      */
-    public function getScheduleTimeInterval($groupId)
+    private function getScheduleTimeInterval($groupId)
     {
         $scheduleAheadFor = (int)$this->scopeConfig->getValue(
             'system/cron/' . $groupId . '/' . self::XML_PATH_SCHEDULE_AHEAD_FOR,
@@ -562,7 +562,7 @@ public function cleanupDisabledJobs($groupId)
      * @param $jobConfig
      * @return null|string
      */
-    public function getCronExpression($jobConfig)
+    private function getCronExpression($jobConfig)
     {
         $cronExpression = null;
         if (isset($jobConfig['config_path'])) {
@@ -600,7 +600,7 @@ public function cleanupScheduleMismatches()
     /**
      * @return array
      */
-    public function getJobs()
+    private function getJobs()
     {
         if (is_null($this->jobs)) {
             $this->jobs = $this->config->getJobs();