Is SftpClient creates new session for each operation?

[Vsevolod-Tsukanov]

How much sessions and channels will be created for following code:

SSHClient ssh = new SSHClient();
//... connect
SftpCLient sftp = ssh.newSFTPClient();

sftp.ls("sftp/path/file.txt");
sftp.mkdir("path/to/new/dir");

RemoteFile f = sftp.getSFTPEngine().open("/home/sftp/file1");
InputStream is = f.new RemoteFileInputStream(0);