code: public function getInstance(Injector $injector, $name)
      {
          if (null !== $this->provider) {
              return $this->provider->get($name);
          }
  
          if (null != $this->providerClass) {
              $provider = $injector->getInstance($this->providerClass);
              if (!($provider instanceof InjectionProvider)) {
                   throw new BindingException('Configured provider class ' . $this->providerClass . ' for constant ' . $this->name . ' is not an instance of stubbles\ioc\InjectionProvider.');
              }
  
              $this->provider = $provider;
              return $this->provider->get($name);
          }
  
          return $this->value;
      }
docs: returns the created instance
  
  @param   \stubbles\ioc\Injector  $injector
  @param   string                  $name
  @return  mixed