public function sendAssetFrom($fromAddress, $toAddress, $asset, $qty, $nativeAmount = null, $comment = '', $commentTo = '')
    {
        $nativeAmount = $this->findDefaultMinimumPerOutput($nativeAmount);
        return $this->jsonRPCClient->execute("sendassetfrom", array($fromAddress, $toAddress, $asset, $qty, $nativeAmount, $comment, $commentTo));
    }