How to use the relstorage.adapters.postgresql.PostgreSQLAdapter function in RelStorage

def RelStorageConfigurationFactory(key, dbconfig):
    if not RELSTORAGE:
        raise Exception("You must install the relstorage package before you can use "
                        "it as a dabase adapter.")
    config = dbconfig.get('configuration', {})
    options = Options(**dbconfig['options'])
    if dbconfig['type'] == 'postgres':
        from relstorage.adapters.postgresql import PostgreSQLAdapter
        dsn = "dbname={dbname} user={user} host={host} password={password} port={port}".format(**dbconfig['dsn'])  # noqa
        adapter = PostgreSQLAdapter(dsn=dsn, options=options)
    rs = RelStorage(adapter=adapter, options=options)
    db = DB(rs)
    try:
        conn = db.open()
        rootobj = conn.root()
        if not IDatabase.providedBy(rootobj):
            alsoProvides(rootobj, IDatabase)
        transaction.commit()
    except:  # noqa
        pass
    finally:
        rootobj = None
        conn.close()
        db.close()
    rs = RelStorage(adapter=adapter, options=options)
    db = RequestAwareDB(rs, **config)

def open(self, databases=None):
        db = self.config.db
        db.name = db.name or self.name
        db = db.open(databases)
        assert (
            isinstance(db.storage,
                       relstorage.storage.RelStorage)
            and
            isinstance(db.storage._adapter,
                       relstorage.adapters.postgresql.PostgreSQLAdapter)
            ), "Invalid storage"
        from ._db import NewtDB
        return NewtDB(db)

import relstorage.adapters.postgresql
import relstorage.adapters.postgresql.mover
import relstorage.adapters.postgresql.schema

from .jsonpickle import Jsonifier
from ._util import trigger_exists

class Adapter(relstorage.adapters.postgresql.PostgreSQLAdapter):

    def __init__(self, *args, **kw):
        super(Adapter, self).__init__(*args, **kw)

        driver = relstorage.adapters.postgresql.select_driver(self.options)
        self.schema = SchemaInstaller(
            connmanager=self.connmanager,
            runner=self.runner,
            locker=self.locker,
            keep_history=self.keep_history,
        )
        self.mover = Mover(
            database_type='postgresql',
            options=self.options,
            runner=self.runner,
            version_detector=self.version_detector,

def factory(options):
                return PostgreSQLAdapter(dsn=dsn, options=options)
            return factory, unused