Level 9 with checkExplicitMixed

Author: ondrejmirtes

conf/config.level9.neon

@@ -0,0 +1,5 @@
+includes:
+	- config.level8.neon
+
+parameters:
+	checkExplicitMixed: true

conf/config.levelmax.neon

@@ -1,2 +1,2 @@
 includes:
-	- config.level8.neon
+	- config.level9.neon

src/Testing/LevelsTestCase.php

@@ -47,7 +47,7 @@ public function testLevels(
 
 		$exceptions = [];
 
-		foreach (range(0, 8) as $level) {
+		foreach (range(0, 9) as $level) {
 			unset($outputLines);
 			exec(sprintf('%s %s clear-result-cache %s 2>&1', escapeshellarg(PHP_BINARY), $command, $configPath !== null ? '--configuration ' . escapeshellarg($configPath) : ''), $clearResultCacheOutputLines, $clearResultCacheExitCode);
 			if ($clearResultCacheExitCode !== 0) {