public function bind($username, $password)
    {
        // Tries to run the LDAP Connection as TLS
        if ($this->tls) {
            if ( ! ldap_start_tls($this->connection)) {
                throw new ConnectionException('Unable to Connect to LDAP using TLS.');
            }
        }

        try {
            $this->bound = ldap_bind($this->connection, $username, $password);
        } catch (ErrorException $e) {
            $this->bound = false;
        }

        return $this->bound;
    }