Export the lcopt model in the native brightway 2 format

        returns name, database

        to use it to export, then import to brightway::

            name, db = model.export_to_bw2()
            import brightway2 as bw
            bw.projects.set_current('MyProject')
            new_db = bw.Database(name)
            new_db.write(db)
            new_db.process()

def export_to_bw2(self):
        """
        Export the lcopt model in the native brightway 2 format

        returns name, database

        to use it to export, then import to brightway::

            name, db = model.export_to_bw2()
            import brightway2 as bw
            bw.projects.set_current('MyProject')
            new_db = bw.Database(name)
            new_db.write(db)
            new_db.process()

        """
        my_exporter = Bw2Exporter(self)
        name, bw2db = my_exporter.export_to_bw2()
        return name, bw2db