my $db_obj = MyApp::BerkeleyDB->connect("dbname.db");
    ....
    # then I can use BerkeleyDB internal methods
    $db_obj->db_put('key', 'value');
    ....
    # use my own functions..
    $db_obj->myfunc("src", ...);
    ....

##</code><code>##

package Myapp::BerkeleyDB
use warnings;
use strict;

use base 'BerkeleyDB';
use BerkeleyDB;

# the following code apparently not working!!!
sub connect
{
    my ($class, $dbname) = @_;
    return new BerkeleyDB::Btree
               -Filename => $dbname,
               ......
         or undef;
}