Install psalm as dev, sync scripts updates

vendor/sebastian/diff/src/Line.php

@@ -0,0 +1,37 @@
+<?php declare(strict_types=1);
+/*
+ * This file is part of sebastian/diff.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+namespace SebastianBergmann\Diff;
+
+final class Line
+{
+    public const ADDED = 1;
+
+    public const REMOVED = 2;
+
+    public const UNCHANGED = 3;
+    private int $type;
+    private string $content;
+
+    public function __construct(int $type = self::UNCHANGED, string $content = '')
+    {
+        $this->type    = $type;
+        $this->content = $content;
+    }
+
+    public function getContent(): string
+    {
+        return $this->content;
+    }
+
+    public function getType(): int
+    {
+        return $this->type;
+    }
+}