upgrade to laravel 7 and set branch to v2

vendor/symfony/http-kernel/DataCollector/DumpDataCollector.php

@@ -27,7 +27,7 @@ use Symfony\Component\VarDumper\Server\Connection;
 /**
  * @author Nicolas Grekas <p@tchwork.com>
  *
- * @final since Symfony 4.3
+ * @final
  */
 class DumpDataCollector extends DataCollector implements DataDumperInterface
 {
@@ -100,12 +100,7 @@ class DumpDataCollector extends DataCollector implements DataDumperInterface
         }
     }
 
-    /**
-     * {@inheritdoc}
-     *
-     * @param \Throwable|null $exception
-     */
-    public function collect(Request $request, Response $response/*, \Throwable $exception = null*/)
+    public function collect(Request $request, Response $response, \Throwable $exception = null)
     {
         if (!$this->dataCount) {
             $this->data = [];
@@ -187,12 +182,12 @@ class DumpDataCollector extends DataCollector implements DataDumperInterface
         self::__construct($this->stopwatch, $fileLinkFormat, $charset);
     }
 
-    public function getDumpsCount()
+    public function getDumpsCount(): int
     {
         return $this->dataCount;
     }
 
-    public function getDumps($format, $maxDepthLimit = -1, $maxItemsPerDepth = -1)
+    public function getDumps($format, $maxDepthLimit = -1, $maxItemsPerDepth = -1): array
     {
         $data = fopen('php://memory', 'r+b');
 
@@ -219,7 +214,7 @@ class DumpDataCollector extends DataCollector implements DataDumperInterface
         return $dumps;
     }
 
-    public function getName()
+    public function getName(): string
     {
         return 'dump';
     }