Cost units can be edited

app/Models/User.php

@@ -2,6 +2,7 @@
 
 namespace App\Models;
 
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Foundation\Auth\User as Authenticatable;
 use Illuminate\Notifications\Notifiable;
 
@@ -95,7 +96,7 @@ class User extends Authenticatable
     public function getFullname() : string {
         return sprintf('%1$1s %2$s %3$s',
             $this->firstname,
-            $this->nickname !== '' ? '('  . $this->nickname . ')' : '',
+            $this->nickname !== null ? '('  . $this->nickname . ')' : '',
             $this->lastname
         );
     }
@@ -103,4 +104,14 @@ class User extends Authenticatable
     public function getNicename() : string {
         return $this->nickname ?? $this->firstname;
     }
+
+    public function localGroup() : Tenant {
+        return $this->belongsTo(Tenant::class, 'local_group', 'slug')->first();
+    }
+
+    public function costUnits()
+    {
+        return $this->belongsToMany(CostUnit::class, 'cost_unit_treasurers', 'user_id', 'cost_unit_id')
+            ->withTimestamps();
+    }
 }