Nelmio\Alice\ParameterBag::has PHP Method

    public function has(string $key) : bool
    {
        return array_key_exists($key, $this->parameters);
    }

 /**
  * @inheritdoc
  */
 public function resolve(ParameterBag $unresolvedParameters, ParameterBag $injectedParameters = null) : ParameterBag
 {
     if (null === $injectedParameters) {
         $injectedParameters = new ParameterBag();
     }
     foreach ($injectedParameters as $injectedParameterKey => $injectedParameterValue) {
         if ($unresolvedParameters->has($injectedParameterKey)) {
             $injectedParameters = $injectedParameters->without($injectedParameterKey);
         }
     }
     return $this->resolver->resolve($unresolvedParameters, $injectedParameters);
 }