sub load {
    my $class = shift;
    return $class->set_error( "called as instance method")    if ref $class;
    return $class->set_error( "Too many arguments provided to load()")  if @_ > 5;

    my $self = bless {
        _DATA       => {
            _SESSION_ID     => undef,
            _SESSION_CTIME  => undef,
            _SESSION_ATIME  => undef,
            _SESSION_REMOTE_ADDR => $ENV{REMOTE_ADDR} || "",
            #
            # Following two attributes may not exist in every single session, and declaring
            # them now will force these to get serialized into database, wasting space. But they
            # are here to remind the coder of their purpose
            #
#            _SESSION_ETIME  => undef,
#            _SESSION_EXPIRE_LIST => {}
        },          # session data
        _DSN        => {},          # parsed DSN params
        _OBJECTS    => {},          # keeps necessary objects
        _DRIVER_ARGS=> {},          # arguments to be passed to driver
        _CLAIMED_ID => undef,       # id **claimed** by client
        _STATUS     => STATUS_UNSET,# status of the session object
        _QUERY      => undef        # query object
    }, $class;

##</code><code>##

    # checking for expiration ticker
    if ( $self->{_DATA}->{_SESSION_ETIME} ) {
        if ( ($self->{_DATA}->{_SESSION_ATIME} + $self->{_DATA}->{_SESSION_ETIME}) <= time() ) {
            $self->_set_status( STATUS_EXPIRED |    # <-- so client can detect expired sessions
                STATUS_DELETED );                   # <-- session should be removed from database
            $self->flush();                         # <-- flush() will do the actual removal!
            return $self;
        }
    }


##</code><code>##

sub flush {
    my $self = shift;

    # Would it be better to die or err if something very basic is wrong here? 
    # I'm trying to address the DESTROY related warning
    # from: http://rt.cpan.org/Ticket/Display.html?id=17541
    # return unless defined $self;

    return unless $self->id;            # <-- empty session
    
    # neither new, nor deleted nor modified
    return if !defined($self->{_STATUS}) or $self->{_STATUS} == STATUS_UNSET;

    if ( $self->_test_status(STATUS_NEW) && $self->_test_status(STATUS_DELETED) ) {
        $self->{_DATA} = {};
        return $self->_unset_status(STATUS_NEW | STATUS_DELETED);
    }

    my $driver      = $self->_driver();
    my $serializer  = $self->_serializer();

    if ( $self->_test_status(STATUS_DELETED) ) {
        defined($driver->remove($self->id)) or
            return $self->set_error( "flush(): couldn't remove session data: " . $driver->errstr );
        $self->{_DATA} = {};                        # <-- removing all the data, making sure
                                                    # it won't be accessible after flush()
        return $self->_unset_status(STATUS_DELETED);
    }

    if ( $self->_test_status(STATUS_NEW | STATUS_MODIFIED) ) {
        my $datastr = $serializer->freeze( $self->dataref );
        unless ( defined $datastr ) {
            return $self->set_error( "flush(): couldn't freeze data: " . $serializer->errstr );
        }
        defined( $driver->store($self->id, $datastr) ) or
            return $self->set_error( "flush(): couldn't store datastr: " . $driver->errstr);
        $self->_unset_status(STATUS_NEW | STATUS_MODIFIED);
    }
    return 1;
}