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

vendor/phpspec/prophecy/spec/Prophecy/Doubler/ClassPatch/TraversablePatchSpec.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace spec\Prophecy\Doubler\ClassPatch;
+
+use PhpSpec\ObjectBehavior;
+use Prophecy\Argument;
+
+class TraversablePatchSpec extends ObjectBehavior
+{
+    function it_is_a_patch()
+    {
+        $this->shouldBeAnInstanceOf('Prophecy\Doubler\ClassPatch\ClassPatchInterface');
+    }
+
+    /**
+     * @param \Prophecy\Doubler\Generator\Node\ClassNode $node
+     */
+    function it_supports_class_that_implements_only_Traversable($node)
+    {
+        $node->getInterfaces()->willReturn(array('Traversable'));
+
+        $this->supports($node)->shouldReturn(true);
+    }
+
+    /**
+     * @param \Prophecy\Doubler\Generator\Node\ClassNode $node
+     */
+    function it_does_not_support_class_that_implements_Iterator($node)
+    {
+        $node->getInterfaces()->willReturn(array('Traversable', 'Iterator'));
+
+        $this->supports($node)->shouldReturn(false);
+    }
+
+    /**
+     * @param \Prophecy\Doubler\Generator\Node\ClassNode $node
+     */
+    function it_does_not_support_class_that_implements_IteratorAggregate($node)
+    {
+        $node->getInterfaces()->willReturn(array('Traversable', 'IteratorAggregate'));
+
+        $this->supports($node)->shouldReturn(false);
+    }
+
+    function it_has_100_priority()
+    {
+        $this->getPriority()->shouldReturn(100);
+    }
+
+    /**
+     * @param \Prophecy\Doubler\Generator\Node\ClassNode $node
+     */
+    function it_forces_node_to_implement_IteratorAggregate($node)
+    {
+        $node->addInterface('Iterator')->shouldBeCalled();
+
+        $node->addMethod(Argument::type('Prophecy\Doubler\Generator\Node\MethodNode'))->willReturn(null);
+
+        $this->apply($node);
+    }
+}