Use static methods inside data providers

Author: OskarStark

Tests/Caster/CasterTest.php

@@ -22,7 +22,7 @@ class CasterTest extends TestCase
 {
     use VarDumperTestTrait;
 
-    private $referenceArray = [
+    private static $referenceArray = [
         'null' => null,
         'empty' => false,
         'public' => 'pub',
@@ -38,12 +38,12 @@ class CasterTest extends TestCase
     public function testFilter($filter, $expectedDiff, $listedProperties = null)
     {
         if (null === $listedProperties) {
-            $filteredArray = Caster::filter($this->referenceArray, $filter);
+            $filteredArray = Caster::filter(self::$referenceArray, $filter);
         } else {
-            $filteredArray = Caster::filter($this->referenceArray, $filter, $listedProperties);
+            $filteredArray = Caster::filter(self::$referenceArray, $filter, $listedProperties);
         }
 
-        $this->assertSame($expectedDiff, array_diff_assoc($this->referenceArray, $filteredArray));
+        $this->assertSame($expectedDiff, array_diff_assoc(self::$referenceArray, $filteredArray));
     }
 
     public function provideFilter()
@@ -126,7 +126,7 @@ public function provideFilter()
             ],
             [
                 Caster::EXCLUDE_NOT_IMPORTANT | Caster::EXCLUDE_VERBOSE,
-                $this->referenceArray,
+                self::$referenceArray,
                 ['public', "\0*\0protected"],
             ],
             [