/**
  * get server capabilities and namespace
  *
  * @return array
  */
 public function getCapabilityAndNamespace()
 {
     $capabilities = $this->_protocol->capability();
     $result = array('capabilities' => $capabilities);
     if (in_array('NAMESPACE', $capabilities)) {
         if ($namespace = $this->_protocol->getNamespace()) {
             $result['namespace'] = $namespace;
         }
     }
     return $result;
 }