'Get the association with the specified handle.
@type assoc_handle: str
@param dumb: Is this association used with dumb mode?
@type dumb: bool
@returns: the association, or None if no valid association with that
handle was found.
@returntype: L{openid.association.Association}'

def getAssociation(self, assoc_handle, dumb, checkExpiration=True):

    if (assoc_handle is None):
        raise ValueError('assoc_handle    must    not    be    None')
    if dumb:
        key = self._dumb_key
    else:
        key = self._normal_key
    assoc = self.store.getAssociation(key, assoc_handle)
    if ((assoc is not None) and (assoc.expiresIn <= 0)):
        oidutil.log(('requested    %sdumb    key    %r    is    expired    (by    %s    seconds)' % ((((not dumb) and 'not-') or ''), assoc_handle, assoc.expiresIn)))
        if checkExpiration:
            self.store.removeAssociation(key, assoc_handle)
            assoc = None
    return assoc
