my $attrs = Net::SFTP::Attributes->new(Stat => [ stat "test.file" ]);
        print "*** file permisions: " . Dumper($attrs) ."\n";
        $attrs->perm( [ '0777' ] ); # what format is this?
        $sftp->do_setstat('test.file', $attrs);
        $attrs = Net::SFTP::Attributes->new(Stat => [ stat "test.file" ]);
        print "*** file permisions: " . ($attrs->{'perm'}) ."\n";