NAME

         GO::Model::Xref - cross reference to an external database

SYNOPSIS

         my $xrefs = $term->dbxref_list();
         foreach my $xref (@$xrefs) P
           printf "Term %s has an xref %s:%s\n",
                   $term->name, $xref->xref_key, $xref->dbname;
         }

DESCRIPTION

       represents a cross reference to an external database. an Xref is made up of a key (ie the
       accession number, or whatever the value of the unique field being keyed off of is) and a
       database name. this should theorerically be enough to uniquely identify any databased
       entity.

NOTES

       Like all the GO::Model::* classes, this uses accessor methods to get or set the
       attributes. by using the accessor method without any arguments gets the value of the
       attribute. if you pass in an argument, then the attribuet will be set according to that
       argument.

       for instance

         # this sets the value of the attribute
         $my_object->attribute_name("my value");

         # this gets the value of the attribute
         $my_value = $my_object->attribute_name();

   xref_key
         Alias   - acc
         Alias   - accession
         Usage   -
         Returns -
         Args    -

        accessor: gets/sets the key/id of the cross reference

   xref_keytype
         Usage   -
         Returns -
         Args    -

        accessor: gets/sets the key/id type of the cross reference

   as_str
         Usage   -
         Returns -
         Args    -

   xref_dbname
         Alias   - dbname
         Usage   -
         Returns -
         Args    -

        accessor: gets/sets the database name of the cross reference

       must be a valid database name

   xref_desc
         Alias   - name
         Usage   -
         Returns -
         Args    -

        accessor: gets/sets the description of the accession no

       useful for interpro

   to_xml
         Usage   - print $xref->to_xml()
         Returns - string
         Args    - indent [integer]

       XML representation; you probably shouldnt call this directly, this will be called by
       entities that own xrefs