Support for PHP infection testing

src/Rclone/Rclone.php

@@ -18,6 +18,7 @@ use Exception;
  */
 class Rclone
 {
+    private const MAX_RUNTIME = 4 * 3600; //4 hours maximum
     protected string $version = "";
 
     /**
@@ -107,7 +108,7 @@ class Rclone
      *
      * @return Process Instance.
      */
-    protected function exec(string $command, array $options = array()): Process
+    private function exec(string $command, array $options = array()): Process
     {
         $process = new Process(
             array_merge(
@@ -119,7 +120,7 @@ class Rclone
 
         $this->logger->info("Execute command", [$process->getCommandLine()]);
 
-        $process->setTimeout(4 * 3600);
+        $process->setTimeout(self::MAX_RUNTIME);
         $process->run();
 
         // executes after the command finishes