Code review changes

tests/Spout/Writer/XLSX/WriterPerfTest.php

@@ -135,7 +135,7 @@ class WriterPerfTest extends TestCase
         copy($filePath, $tmpFile);
 
         // Get the last 200 characters
-        $lastCharacters = `tail -c $numCharacters $tmpFile`;
+        $lastCharacters = shell_exec("tail -c $numCharacters $tmpFile");
 
         // remove the temporary file
         unlink($tmpFile);

tests/Spout/Writer/XLSX/WriterWithStyleTest.php

@@ -32,7 +32,7 @@ class WriterWithStyleTest extends TestCase
     /**
      * @return void
      */
-    public function setUp(): void
+    public function setUp() : void
     {
         $this->defaultStyle = (new StyleBuilder())->build();
     }