public function serviceExists(string $serviceName): bool {
        return isset($this->serviceData[$serviceName]) || in_array($serviceName, $this->getSelfReferenceNames()) ? true : false;
    }
public function serviceExists(string $serviceName): bool {
        return isset($this->serviceData[$serviceName]) || in_array($serviceName, $this->getSelfReferenceNames()) ? true : false;
    }
public function serviceExists ( string $ serviceName ) : bool { return isset ( $ this -> serviceData [ $ serviceName ] ) || in_array ( $ serviceName , $ this -> getSelfReferenceNames ( ) ) ? true : false ; }
Looks, if a service with the given name is available
@param string $serviceName
@return bool
Looks if a service with the given name is available