public function isCoreModules(array $modules)
    {
        foreach ($modules as $module) {
            if (!$this->isCoreModule($module)) {
                return false;
            }
        }

        return true;
    }
public function isCoreModules(array $modules)
    {
        foreach ($modules as $module) {
            if (!$this->isCoreModule($module)) {
                return false;
            }
        }

        return true;
    }
public function isCoreModules ( array $ modules ) { foreach ( $ modules as $ module ) { if ( ! $ this -> isCoreModule ( $ module ) ) { return false ; } } return true ; }
Checks whether all collection consists of core modules

@param string $modules A collection of module names
@throws \InvalidArgumentException If $module isn't a string
@return boolean
Checks whether all collection consists of core modules