Zend\Code\Generator\ClassGenerator::addMethodFromGenerator PHP Method

    public function addMethodFromGenerator(MethodGenerator $method)
    {
        $methodName = $method->getName();
        if ($this->hasMethod($methodName)) {
            throw new Exception\InvalidArgumentException(sprintf('A method by name %s already exists in this class.', $methodName));
        }
        $this->methods[strtolower($methodName)] = $method;
        return $this;
    }

 /**
  * {@inheritdoc}
  */
 public function generate(ReflectionClass $originalClass, ClassGenerator $classGenerator)
 {
     CanProxyAssertion::assertClassCanBeProxied($originalClass);
     $classGenerator->setExtendedClass($originalClass->getName());
     $additionalInterfaces = ['OpenClassrooms\\ServiceProxy\\ServiceProxyInterface'];
     $additionalProperties['proxy_realSubject'] = new PropertyGenerator('proxy_realSubject', null, PropertyGenerator::FLAG_PRIVATE);
     $additionalMethods['setProxy_realSubject'] = new MethodGenerator('setProxy_realSubject', [['name' => 'realSubject']], MethodGenerator::FLAG_PUBLIC, '$this->proxy_realSubject = $realSubject;');
     $methods = $originalClass->getMethods(\ReflectionMethod::IS_PUBLIC);
     foreach ($methods as $method) {
         $preSource = '';
         $postSource = '';
         $exceptionSource = '';
         $methodAnnotations = $this->annotationReader->getMethodAnnotations($method);
         foreach ($methodAnnotations as $methodAnnotation) {
             if ($methodAnnotation instanceof Cache) {
                 $additionalInterfaces['cache'] = 'OpenClassrooms\\ServiceProxy\\ServiceProxyCacheInterface';
                 $response = $this->cacheStrategy->execute($this->serviceProxyStrategyRequestBuilder->create()->withAnnotation($methodAnnotation)->withClass($originalClass)->withMethod($method)->build());
                 foreach ($response->getMethods() as $methodToAdd) {
                     $additionalMethods[$methodToAdd->getName()] = $methodToAdd;
                 }
                 foreach ($response->getProperties() as $propertyToAdd) {
                     $additionalProperties[$propertyToAdd->getName()] = $propertyToAdd;
                 }
                 $preSource .= $response->getPreSource();
                 $postSource .= $response->getPostSource();
                 $exceptionSource .= $response->getExceptionSource();
             }
         }
         $classGenerator->addMethodFromGenerator($this->generateProxyMethod($method, $preSource, $postSource, $exceptionSource));
     }
     $classGenerator->setImplementedInterfaces($additionalInterfaces);
     $classGenerator->addProperties($additionalProperties);
     $classGenerator->addMethods($additionalMethods);
 }