Test for internal TypeMapArrayIterator class

This class was originally added in PHPLIB-112

tests/Model/TypeMapArrayIteratorTest.php

+<?php
+
+namespace MongoDB\Tests;
+
+use MongoDB\Model\TypeMapArrayIterator;
+
+class TypeMapArrayIteratorTest extends TestCase
+{
+    public function testCurrentAppliesTypeMap()
+    {
+        $document = [
+            'array' => [1, 2, 3],
+            'object' => ['foo' => 'bar'],
+        ];
+
+        $typeMap = [
+            'root' => 'object',
+            'document' => 'object',
+            'array' => 'array',
+        ];
+
+        $iterator = new TypeMapArrayIterator([$document], $typeMap);
+
+        $expectedDocument = (object) [
+            'array' => [1, 2, 3],
+            'object' => (object) ['foo' => 'bar'],
+        ];
+
+        $iterator->rewind();
+
+        $this->assertEquals($expectedDocument, $iterator->current());
+    }
+}