public function append(string $postfix): Utility
    {
        return new static($this->string . new static($postfix, $this->encoding), $this->encoding);
    }
public function append(string $postfix): Utility
    {
        return new static($this->string . new static($postfix, $this->encoding), $this->encoding);
    }
public function append ( string $ postfix ) : Utility { return new static ( $ this -> string . new static ( $ postfix , $ this -> encoding ) , $ this -> encoding ) ; }
Append the string with a given value

@param string $postfix Value to append to the string

@return $this
Append the string with a given value