diff --git a/src/Aviat/Ion/Di/Container.php b/src/Aviat/Ion/Di/Container.php
index 098cfd3d..b80716cd 100644
--- a/src/Aviat/Ion/Di/Container.php
+++ b/src/Aviat/Ion/Di/Container.php
@@ -3,8 +3,6 @@
 namespace Aviat\Ion\Di;
 
 use ArrayObject;
-use Aviat\Ion\Di\Exception\ContainerException;
-use Aviat\Ion\Di\Exception\NotFoundException;
 
 /**
  * Dependency container
@@ -50,7 +48,7 @@ class Container implements ContainerInterface {
 			return $this->container[$id];
 		}
 
-		throw new Exception\NotFoundException("Item {$id} does not exist in container.");
+		throw new Exception\NotFoundException("Item '{$id}' does not exist in container.");
 	}
 
 	/**
diff --git a/src/Aviat/Ion/Transformer/AbstractTransformer.php b/src/Aviat/Ion/Transformer/AbstractTransformer.php
new file mode 100644
index 00000000..ed6997a2
--- /dev/null
+++ b/src/Aviat/Ion/Transformer/AbstractTransformer.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace Aviat\Ion\Transformer;
+
+abstract class AbstractTransformer implements TransformerInterface {
+
+	/**
+	 * Mutate the data structure
+	 *
+	 * @param array|object $item
+	 * @return mixed
+	 */
+	abstract public function transform($item);
+
+	/**
+	 * Transform a set of structures
+	 *
+	 * @param  array|object $collection
+	 * @return array
+	 */
+	public function transform_collection($collection)
+	{
+		$list = (array) $collection;
+		return array_map([$this, 'transform'], $list);
+	}
+}
+// End of AbstractTransformer.php
\ No newline at end of file
diff --git a/src/Aviat/Ion/Transformer/TransformerInterface.php b/src/Aviat/Ion/Transformer/TransformerInterface.php
new file mode 100644
index 00000000..4f028ce5
--- /dev/null
+++ b/src/Aviat/Ion/Transformer/TransformerInterface.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace Aviat\Ion\Transformer;
+
+interface TransformerInterface {
+
+	/**
+	 * Mutate the data structure
+	 *
+	 * @param array|object $item
+	 * @return mixed
+	 */
+	public function transform($item);
+}
\ No newline at end of file
diff --git a/tests/Ion/Di/ContainerAwareTest.php b/tests/Ion/Di/ContainerAwareTest.php
new file mode 100644
index 00000000..dd506721
--- /dev/null
+++ b/tests/Ion/Di/ContainerAwareTest.php
@@ -0,0 +1,39 @@
+<?php
+
+use Aviat\Ion\Di\Container;
+use Aviat\Ion\Di\ContainerAware;
+use Aviat\Ion\Di\ContainerInterface;
+use Aviat\Ion\Di\Exception\ContainerException;
+
+class Aware {
+	use ContainerAware;
+	
+	public function __construct(ContainerInterface $container)
+	{
+		$this->container = $container;
+	}
+}
+
+
+class ContainerAwareTest extends AnimeClient_TestCase {
+	
+	public function setUp()
+	{
+		$this->container = new Container();
+		$this->aware = new Aware($this->container);
+	}
+	
+	public function testContainerAwareTrait()
+	{
+		// The container was set in setup
+		// check that the get method returns the same
+		$this->assertSame($this->container, $this->aware->getContainer());
+		
+		$container2 = new Container([
+			'foo' => 'bar',
+			'baz' => 'foobar'
+		]);
+		$this->aware->setContainer($container2);
+		$this->assertSame($container2, $this->aware->getContainer());
+	}
+}
\ No newline at end of file
diff --git a/tests/Ion/Di/ContainerTest.php b/tests/Ion/Di/ContainerTest.php
new file mode 100644
index 00000000..f01cca74
--- /dev/null
+++ b/tests/Ion/Di/ContainerTest.php
@@ -0,0 +1,51 @@
+<?php
+
+use Aviat\Ion\Di\Container;
+use Aviat\Ion\Di\Exception\ContainerException;
+
+
+class ContainerTest extends AnimeClient_TestCase {
+
+	public function setUp()
+	{
+		$this->container = new Container();
+	}
+
+	public function dataGetWithException()
+	{
+		return [
+			'Bad index type: number' => [
+				'id' => 42,
+				'exception' => 'Aviat\Ion\Di\Exception\ContainerException',
+				'message' => 'Id must be a string'
+			],
+			'Bad index type: array' => [
+				'id' => [],
+				'exception' => 'Aviat\Ion\Di\Exception\ContainerException',
+				'message' => 'Id must be a string'
+			],
+			'Non-existent id' => [
+				'id' => 'foo',
+				'exception' => 'Aviat\Ion\Di\Exception\NotFoundException',
+				'message' => "Item 'foo' does not exist in container."
+			]
+		];
+	}
+
+	/**
+	 * @dataProvider dataGetWithException
+	 */
+	public function testGetWithException($id, $exception, $message)
+	{
+		try
+		{
+			$this->container->get($id);
+		}
+		catch(ContainerException $e)
+		{
+			$this->assertInstanceOf($exception, $e);
+			$this->assertEquals($message, $e->getMessage());
+		}
+	}
+
+}
\ No newline at end of file
diff --git a/tests/Ion/Transformer/AbstractTransformerTest.php b/tests/Ion/Transformer/AbstractTransformerTest.php
new file mode 100644
index 00000000..56c1104d
--- /dev/null
+++ b/tests/Ion/Transformer/AbstractTransformerTest.php
@@ -0,0 +1,107 @@
+<?php
+
+use Aviat\Ion\Transformer\AbstractTransformer;
+
+class TestTransformer extends AbstractTransformer {
+	
+	public function transform($item)
+	{
+		$out = [];
+		$genre_list = (array) $item;
+		
+		foreach($genre_list as $genre)
+		{
+			$out[] = $genre['name'];
+		}
+		
+		return $out;
+	}
+}
+
+class AbstractTransformerTest extends AnimeClient_TestCase {
+	
+	protected $transformer;
+
+
+	public function setUp()
+	{
+		$this->transformer = new TestTransformer();
+	}
+	
+	public function dataTransformCollection()
+	{
+		return [
+			'object' => [
+				'original' => [
+					(object)[
+						['name' => 'Comedy'],
+						['name' => 'Romance'],
+						['name' => 'School'],
+						['name' => 'Harem']
+					],
+					(object)[
+						['name' => 'Action'],
+						['name' => 'Comedy'],
+						['name' => 'Magic'],
+						['name' => 'Fantasy'],
+						['name' => 'Mahou Shoujo']
+					],
+					(object)[
+						['name' => 'Comedy'],
+						['name' => 'Sci-Fi']
+					]
+				],
+				'expected' => [
+					['Comedy', 'Romance', 'School', 'Harem'],
+					['Action', 'Comedy', 'Magic', 'Fantasy', 'Mahou Shoujo'],
+					['Comedy', 'Sci-Fi']
+				]
+			],
+			'array' => [
+				'original' => [
+					[
+						['name' => 'Comedy'],
+						['name' => 'Romance'],
+						['name' => 'School'],
+						['name' => 'Harem']
+					],
+					[
+						['name' => 'Action'],
+						['name' => 'Comedy'],
+						['name' => 'Magic'],
+						['name' => 'Fantasy'],
+						['name' => 'Mahou Shoujo']
+					],
+					[
+						['name' => 'Comedy'],
+						['name' => 'Sci-Fi']
+					]
+				],
+				'expected' => [
+					['Comedy', 'Romance', 'School', 'Harem'],
+					['Action', 'Comedy', 'Magic', 'Fantasy', 'Mahou Shoujo'],
+					['Comedy', 'Sci-Fi']
+				]
+			],
+		];
+	}
+	
+	public function testTransform()
+	{
+		$data = $this->dataTransformCollection();
+		$original = $data['object']['original'][0];
+		$expected = $data['object']['expected'][0];
+		
+		$actual = $this->transformer->transform($original);
+		$this->assertEquals($expected, $actual);
+	}
+
+	/**
+	 * @dataProvider dataTransformCollection
+	 */
+	public function testTransformCollection($original, $expected)
+	{
+		$actual = $this->transformer->transform_collection($original);
+		$this->assertEquals($expected, $actual);
+	}
+}
\ No newline at end of file