public function get($key = null)
    {
        if ($key === null) {
            return $this;
        }
        
        if (!isset($this->modules[$key])) {
            throw new ModuleDoesntExistException($key);
        }
        
        return $this->modules[$key];
    }
public function get($key = null)
    {
        if ($key === null) {
            return $this;
        }
        
        if (!isset($this->modules[$key])) {
            throw new ModuleDoesntExistException($key);
        }
        
        return $this->modules[$key];
    }
public function get ( $ key = null ) { if ( $ key === null ) { return $ this ; } if ( ! isset ( $ this -> modules [ $ key ] ) ) { throw new ModuleDoesntExistException ( $ key ) ; } return $ this -> modules [ $ key ] ; }
Retrieve a registered module

@param  string|null $key
@return \GibbonCms\Gibbon\Modules\Module|self
Retrieve a registered module