Add meta relation to all models

app/Models/Metric.php

@@ -165,6 +165,16 @@ class Metric extends Model implements HasPresenter
         });
     }
 
+    /**
+     * Get all of the meta relation.
+     *
+     * @return \Illuminate\Database\Eloquent\Relations\MorphMany
+     */
+    public function meta()
+    {
+        return $this->morphMany(Meta::class, 'meta');
+    }
+
     /**
      * Get the points relation.
      *