'Dispose of the current :class:`.Session`, if present.
This will first call :meth:`.Session.close` method
on the current :class:`.Session`, which releases any existing
transactional/connection resources still being held; transactions
specifically are rolled back.  The :class:`.Session` is then
discarded.   Upon next usage within the same scope,
the :class:`.scoped_session` will produce a new
:class:`.Session` object.'

def remove(self):

    if self.registry.has():
        self.registry().close()
    self.registry.clear()
