def to(self, device, dtype=None):
        """ Returns a new linear operator with given device and dtype
            WARNING: dtype change is not supported yet. """
        params, unflatten = self.flatten()
        params = [self.xnp.move_to(p, device=device, dtype=dtype) if self.xnp.is_array(p) else p for p in params]
        return unflatten(params)
 Returns a new linear operator with given device and dtype
            WARNING: dtype change is not supported yet. 
cola/ops/operator_base.py