# returns the new object
sub init {
    my $sftp = shift;
    my %param = @_;
    $sftp->{debug} = delete $param{debug};
    $sftp->{status} = SSH2_FX_OK;

    $param{ssh_args} ||= [];
    $param{ssh_args} = [%{$param{ssh_args}}]
     if UNIVERSAL::isa($param{ssh_args},'HASH');

    $param{warn} = 1 if not defined $param{warn};   # default
    $sftp->{warn_h} = delete $param{warn} || sub {};  # false => ignore
    $sftp->{warn_h} = sub { carp $_[1] }  # true  => emit warning
     if $sftp->{warn_h} and not ref $sftp->{warn_h};

    $sftp->{_msg_id} = 0;

    my $ssh = Net::SSH::Perl->new($sftp->{host}, protocol => 2,
        debug => $sftp->{debug}, @{ $param{ssh_args} });
    $ssh->login($param{user}, $param{password}, 'supress_shell'); #line 62
    $sftp->{ssh} = $ssh;

    my $channel = $sftp->_open_channel;
    $sftp->{channel} = $channel;

    $sftp->do_init;

    $sftp;
}