Added more header stuff (requires and uses) along with a forgotten PartialPlay

PHPSkills/FactorGraphs/FactorGraphLayer.php

@@ -1,6 +1,8 @@
 <?php
 namespace Moserware\Skills\FactorGraphs;
 
+require_once(dirname(__FILE__) . "Schedule.php");
+
 abstract class FactorGraphLayer
 {
     private $_localFactors = array();
@@ -63,5 +65,4 @@ abstract class FactorGraphLayer
     }
 }
 
-
 ?>