[1] isa_ok($sessions_metadata->username,"EP::Common::DBI::Users");

##</code><code>##

[2] isa_ok($sessions_metadata->session_id,"EP::Common::DBI::Sessions");

##</code><code>##

###### Users ####### 
package EP::Common::DBI::Users; 
use strict; 
use warnings; 
use base qw( EP::Common::DBI ); 
__PACKAGE__->table('users');
__PACKAGE__->columns(Primary => qw/username/); 
__PACKAGE__->columns(All => qw/password salt session_only first_name 
last_name institute department address telephone email/);


###### Sessions ########
package EP::Common::DBI::Sessions;
use strict;
use warnings;
use base qw( EP::Common::DBI );
__PACKAGE__->table('sessions');
__PACKAGE__->columns(Primary => qw/id/);
__PACKAGE__->columns(All => qw/a_session/);


######### Sessions_Metadata #################
package EP::Common::DBI::Sessions_Metadata;
use strict;
use warnings;
use base qw( EP::Common::DBI );
#setup table fields
__PACKAGE__->table('sessions_metadata');
__PACKAGE__->columns(Primary => qw/session_id/);
__PACKAGE__->columns(Others => qw/create_date username expire query_id/);
#relations
__PACKAGE__->has_a(username=>'EP::Common::DBI::Users');
__PACKAGE__->has_a(session_id=>'EP::Common::DBI::Sessions');