question: public static void createLesson ( @ NotNull final Lesson lesson , @ NotNull final VirtualFile courseDir , @ NotNull final File resourceRoot , @ NotNull final Project project ) throws IOException { String lessonDirName = EduNames . LESSON + Integer . toString ( lesson . getIndex ( ) ) ; VirtualFile lessonDir = courseDir . createChildDirectory ( project , lessonDirName ) ; final List < Task > taskList = lesson . getTaskList ( ) ; for ( int i = 1 ; i <= taskList . size ( ) ; i ++ ) { Task task = taskList . get ( i - 1 ) ; task . setIndex ( i ) ; createTask ( task , lessonDir , new File ( resourceRoot , lessonDir . getName ( ) ) , project ) ; } }
target:  Creates lesson directory in its course folder in project user created