/**
  * {@inheritdoc}
  */
 public function readContextCallees(ContextEnvironment $environment, $contextClass)
 {
     if (isset($this->cachedCallees[$contextClass])) {
         return $this->cachedCallees[$contextClass];
     }
     return $this->cachedCallees[$contextClass] = $this->childReader->readContextCallees($environment, $contextClass);
 }
 /**
  * {@inheritdoc}
  */
 public function readContextCallees(ContextEnvironment $environment, $contextClass)
 {
     $key = $this->generateCacheKey($environment, $contextClass);
     if (isset($this->cachedCallees[$key])) {
         return $this->cachedCallees[$key];
     }
     return $this->cachedCallees[$key] = $this->childReader->readContextCallees($environment, $contextClass);
 }