decided to leave the posts.discussion_id foreign key constraint to discussions out for now

src/Discussion/Discussion.php

@@ -400,7 +400,7 @@ class Discussion extends AbstractModel
      */
     public function readers()
     {
-        return $this->belongsToMany(User::class, 'discussions_users');
+        return $this->belongsToMany(User::class);
     }
 
     /**

src/Group/Group.php

@@ -121,7 +121,7 @@ class Group extends AbstractModel
      */
     public function users()
     {
-        return $this->belongsToMany(User::class, 'users_groups');
+        return $this->belongsToMany(User::class);
     }
 
     /**

src/Group/Permission.php

@@ -23,7 +23,7 @@ class Permission extends AbstractModel
     /**
      * {@inheritdoc}
      */
-    protected $table = 'groups_permissions';
+    protected $table = 'group_permission';
 
     /**
      * Define the relationship with the group that this permission is for.