public function getChildByIndex($index)
    {
        $index = intval($index);

        return ((null !== $this->children) && array_key_exists($index, $this->children)) ? $this->children[$index] : null;
    }
public function getChildByIndex($index)
    {
        $index = intval($index);

        return ((null !== $this->children) && array_key_exists($index, $this->children)) ? $this->children[$index] : null;
    }
public function getChildByIndex ( $ index ) { $ index = intval ( $ index ) ; return ( ( null !== $ this -> children ) && array_key_exists ( $ index , $ this -> children ) ) ? $ this -> children [ $ index ] : null ; }
Get child Node by Index

@param  int $index 0-n index
@return Node       Node or null if index doesn't exist
Get child Node by Index