public function withGroup($group)
    {
        $group = str_replace('\\', '/', $group);
        if (!isset(static::$instances[$group])) {
            $instance = new static($this->options);
            $instance->setGroup($group);
            static::$instances[$group] = $instance;
        }
        return static::$instances[$group];
    }
public function withGroup($group)
    {
        $group = str_replace('\\', '/', $group);
        if (!isset(static::$instances[$group])) {
            $instance = new static($this->options);
            $instance->setGroup($group);
            static::$instances[$group] = $instance;
        }
        return static::$instances[$group];
    }
public function withGroup ( $ group ) { $ group = str_replace ( '\\' , '/' , $ group ) ; if ( ! isset ( static :: $ instances [ $ group ] ) ) { $ instance = new static ( $ this -> options ) ; $ instance -> setGroup ( $ group ) ; static :: $ instances [ $ group ] = $ instance ; } return static :: $ instances [ $ group ] ; }
with specified group, return new object
@param  string $file
@return static
with specified group return new object