private function _prepareMemcacheNamespaceCollection()
 {
     foreach ($this->configMemcacheNamespaces as $key => $configuration) {
         if ($this->namespaceCollection->has($key)) {
             throw MemcacheCollectionException::duplicateNamespace($key);
         }
         if (!$this->_hasConfiguration('pattern', $configuration)) {
             throw MemcacheCollectionException::missingRequiredNamespaceParameter($key, 'prefix');
         }
         $namespace = new MemcacheNamespace();
         $namespace->setName($key);
         $namespace->setPattern($configuration['pattern']);
         $namespace->setSeparator($this->_getConfiguration('separator', $configuration));
         $variables = $this->_setupMemcacheKeyVariables($namespace->getPattern());
         $namespace->setVariables($variables);
         $this->namespaceCollection->set($key, $namespace);
     }
 }