Storage transactions in Redland's Python bindings?

import RDF, Redland

storage = RDF.Storage(...)
model = RDF.Model(storage)
Redland.librdf_model_transaction_start(model._model)
try:
    # Do something
    Redland.librdf_model_transaction_commit(model._model)
    model.sync()
except:
    Redland.librdf_model_transaction_rollback(model._model)

class Model(object):
  ...
  def transaction_start(self):
    return Redland.librdf_model_transaction_start(self._model)