'Creates a new :class:`~secretstorage.item.Item` with given
`label` (unicode string), `attributes` (dictionary) and `secret`
(bytestring). If `replace` is :const:`True`, replaces the existing
item with the same attributes. If `content_type` is given, also
sets the content type of the secret (``text/plain`` by default).
Returns the created item.'

def create_item(self, label, attributes, secret, replace=False, content_type='text/plain'):

    self.ensure_not_locked()
    if (not self.session):
        self.session = open_session(self.bus)
    secret = format_secret(self.session, secret, content_type)
    attributes = dbus.Dictionary(attributes, signature='ss')
    properties = {(SS_PREFIX + 'Item.Label'): label, (SS_PREFIX + 'Item.Attributes'): attributes}
    (new_item, prompt) = self.collection_iface.CreateItem(properties, secret, replace, signature='a{sv}(oayays)b')
    return Item(self.bus, new_item, self.session)
