public function withIndex(int $index): self
    {
        $state = clone $this;
        $state->_index = $index;
        return $state;
    }
public function withIndex(int $index): self
    {
        $state = clone $this;
        $state->_index = $index;
        return $state;
    }
public function withIndex ( int $ index ) : self { $ state = clone $ this ; $ state -> _index = $ index ; return $ state ; }
Get self with current certification path index set.

@param int $index
@return self
Get self with current certification path index set .