'boolean', 'is_active' => 'boolean', ]; public function course(): BelongsTo { return $this->belongsTo(Course::class); } public function parent(): BelongsTo { return $this->belongsTo(CourseModule::class, 'parent_id'); } public function children(): HasMany { return $this->hasMany(CourseModule::class, 'parent_id'); } public function tests(): HasMany { return $this->hasMany(Test::class); } public function userProgress(): HasMany { return $this->hasMany(UserCourseProgress::class); } }