/**
  * Returns default alias name
  *
  * @return null|string
  * @throws ElasticaManagerNoAliasException
  */
 protected function getDefaultAlias()
 {
     $defaultAlias = $this->configuration->getAlias();
     if (!$defaultAlias) {
         throw new ElasticaManagerNoAliasException($this->configuration->getName());
     }
     return $defaultAlias;
 }
 public function addConfiguration(Configuration $configuration)
 {
     $this->configurations[$configuration->getName()] = $configuration;
 }