Use camelCase in function return_popular_courses

index.php

@@ -141,7 +141,7 @@ if ($useCookieValidation === 'true') {
 if (!isset($_REQUEST['include'])) {
     if (api_get_setting('show_hot_courses') == 'true') {
         if (api_get_configuration_value('popular_courses')) {
-            $hotCourses = $controller->return_popular_courses();
+            $hotCourses = $controller->returnPopularCourses();
         } else {
             $hotCourses = $controller->return_hot_courses();
         }

main/inc/lib/course.lib.php

@@ -4901,7 +4901,7 @@ class CourseManager
      *
      * @return array
      */
-    public static function return_popular_courses()
+    public static function returnPopularCourses()
     {
         if (api_is_invitee()) {
             return [];

main/inc/lib/userportal.lib.php

@@ -1901,9 +1901,9 @@ class IndexManager
     /**
      * @return array
      */
-    public function return_popular_courses()
+    public function returnPopularCourses()
     {
-        return CourseManager::return_popular_courses();
+        return CourseManager::returnPopularCourses();
     }
 
     /**