Mark more fields as protected (#81)

src/Schema.php

@@ -50,38 +50,38 @@ class Schema implements \JsonSerializable, \ArrayAccess {
      */
     private static $DATE_REGEX = '`^\d{4}-\d{2}-\d{2}([ T]\d{2}:\d{2}(:\d{2})?)?`i';
 
-    private $schema = [];
+    protected $schema = [];
 
     /**
      * @var int A bitwise combination of the various **Schema::FLAG_*** constants.
      */
-    private $flags = 0;
+    protected $flags = 0;
 
     /**
      * @var array An array of callbacks that will filter data in the schema.
      */
-    private $filters = [];
+    protected $filters = [];
 
     /**
      * @var array An array of callbacks that will custom validate the schema.
      */
-    private $validators = [];
+    protected $validators = [];
 
     /**
      * @var string|Validation The name of the class or an instance that will be cloned.
      * @deprecated
      */
-    private $validationClass = Validation::class;
+    protected $validationClass = Validation::class;
 
     /**
      * @var callable A callback is used to create validation objects.
      */
-    private $validationFactory = [Validation::class, 'createValidation'];
+    protected $validationFactory = [Validation::class, 'createValidation'];
 
     /**
      * @var callable
      */
-    private $refLookup;
+    protected $refLookup;
 
     /// Methods ///