generate field long name by shop method, assert return type

Modules/Application/Model/D3ManufacturerLongDesc.php

@@ -46,14 +46,7 @@ class D3ManufacturerLongDesc extends D3ManufacturerLongDesc_parent
      */
     public function d3GetLongdesc(): string
     {
-        return $this->getFieldData(Constants::D3_OXMANUFACTURERS_LONGDESC_FIELDNAME);
-    }
-
-    /**
-     * @return string
-     */
-    public function getD3LongDescTableColumnName(): string
-    {
-        return $this->getViewName(true).'__'.Constants::D3_OXMANUFACTURERS_LONGDESC_FIELDNAME;
+        $longName = $this->_getFieldLongName(Constants::D3_OXMANUFACTURERS_LONGDESC_FIELDNAME);
+        return $this->$longName ?: oxNew(Field::class);
     }
 }