def get(self, id, pk='id', deleted=False):
        try:
            if pk == 'id':
                id = int(id)
            if deleted:
                spec = {pk: id}
            else:
                spec = {pk: id, 'data': {'$exists': 1}}
            fields = {'_id': 0}
            row = self.db.docs.find_one(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return Document(**row)
        raise NotFoundError('%s %s not found' % (pk, id))
def _rmsprop_update_numpy(self, var, g, mg, rms, mom, lr, decay, momentum,
                            centered):
    rms_t = rms * decay + (1 - decay) * g * g
    if centered:
      mg_t = mg * decay + (1 - decay) * g
      denom_t = rms_t - mg_t * mg_t
    else:
      mg_t = mg
      denom_t = rms_t
    mom_t = momentum * mom + lr * g / np.sqrt(denom_t, dtype=denom_t.dtype)
    var_t = var - mom_t
    return var_t, mg_t, rms_t, mom_t