working setting type SET in MC settings menu

application/core/Settings/Setting.php

@@ -123,6 +123,15 @@ class Setting {
 		return null;
 	}
 
+	/**
+	 * Get whether the Setting has been persisted at some point
+	 *
+	 * @return bool
+	 */
+	public function isPersisted() {
+		return ($this->index > 0);
+	}
+
 	/**
 	 * Get the Formatted Value of the Setting
 	 *