Rename interfaces and classes in the Predis\Cluster namespace.

A few methods were renamed accordingly for consistency

tests/PHPUnit/DistributorTestCase.php

@@ -0,0 +1,67 @@
+<?php
+
+/*
+ * This file is part of the Predis package.
+ *
+ * (c) Daniele Alessandri <suppakilla@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Predis\Cluster\Distributor;
+
+use PHPUnit_Framework_TestCase as StandardTestCase;
+
+/**
+ *
+ */
+abstract class DistributorTestCase extends StandardTestCase
+{
+    /**
+     * Returns a new instance of the tested distributor.
+     *
+     * @return Predis\Cluster\Distributor\DistributorInterface
+     */
+    protected abstract function getDistributorInstance();
+
+    /**
+     * Returns a list of nodes from the hashring.
+     *
+     * @param DistributorInterface $ring Hashring instance.
+     * @param int $iterations Number of nodes to fetch.
+     * @return array Nodes from the hashring.
+     */
+    protected function getNodes(DistributorInterface $ring, $iterations = 10)
+    {
+        $nodes = array();
+
+        for ($i = 0; $i < $iterations; $i++) {
+            $key = $ring->hash($i * $i);
+            $nodes[] = $ring->get($key);
+        }
+
+        return $nodes;
+    }
+
+    /**
+     * @group disconnected
+     */
+    public function testEmptyRingThrowsException()
+    {
+        $this->setExpectedException('Predis\Cluster\Distributor\EmptyRingException');
+
+        $ring = $this->getDistributorInstance();
+        $ring->get('nodekey');
+    }
+
+    /**
+     * @group disconnected
+     */
+    public function testRemoveOnEmptyRingDoesNotThrowException()
+    {
+        $ring = $this->getDistributorInstance();
+
+        $this->assertNull($ring->remove('node'));
+    }
+}