调用未定义的方法Net_SSH2 :: put（）

I'm using PHP_SSH2 version 1.1.2 (and phpseclib version 1.0.11) and when trying to upload files, I get this error:

PHP Fatal error: Uncaught error: Call to undefined method Net_SSH2::put()

Here is the code I'm using:

require 'Net/SSH2.php';
define('NET_SSH2_LOGGING', NET_SSH2_LOG_COMPLEX);

$connection = new Net_SSH2($ftp_server);
if(!$connection->login($ftp_user_name, $ftp_user_pass)){ 
    die("FTP connection has failed!
Attempted to connect to $ftp_server for user $ftp_user_name"); 
}

$source_file = 'filename.txt';
$destination_file = $source_file;
$upload = $connection->put($destination_file, $source_file, NET_SFTP_LOCAL_FILE);

if (!$upload) die("FTP upload of $source_file has failed!");

I can connect to the server okay (so login() works), but put() doesn't?

Net_SSH2 does not have a put method. You'd need to use Net_SFTP to perform SFTP actions on the SSH server.

http://phpseclib.sourceforge.net/sftp/examples.html#put