public function getNbAddresses(): string
    {
        if ($this->nb_addresses === null) {
            $this->nb_addresses = gmp_strval(gmp_pow(2, $this->getMaxPrefix() - $this->prefix));
        }

        return $this->nb_addresses;
    }
public function getNbAddresses(): string
    {
        if ($this->nb_addresses === null) {
            $this->nb_addresses = gmp_strval(gmp_pow(2, $this->getMaxPrefix() - $this->prefix));
        }

        return $this->nb_addresses;
    }
public function getNbAddresses ( ) : string { if ( $ this -> nb_addresses === null ) { $ this -> nb_addresses = gmp_strval ( gmp_pow ( 2 , $ this -> getMaxPrefix ( ) - $ this -> prefix ) ) ; } return $ this -> nb_addresses ; }
Return the number of IP addresses in the block.

@return string numeric string (can be huge)
Return the number of IP addresses in the block .