Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/phpunit/php-code-coverage/tests/_files/BankAccount.php

@@ -0,0 +1,33 @@
+<?php
+class BankAccount
+{
+    protected $balance = 0;
+
+    public function getBalance()
+    {
+        return $this->balance;
+    }
+
+    protected function setBalance($balance)
+    {
+        if ($balance >= 0) {
+            $this->balance = $balance;
+        } else {
+            throw new RuntimeException;
+        }
+    }
+
+    public function depositMoney($balance)
+    {
+        $this->setBalance($this->getBalance() + $balance);
+
+        return $this->getBalance();
+    }
+
+    public function withdrawMoney($balance)
+    {
+        $this->setBalance($this->getBalance() - $balance);
+
+        return $this->getBalance();
+    }
+}