er solver. Either midpoint or heun. The solver type slightly affects
the sample quality, especially for small number of steps. We empirically find that midpoint solvers are
slightly better, so we recommend to use the midpoint type.


lower_order_final (bool, default True) —
whether to use lower-order solvers in the final steps. Only valid for < 15 inference steps. We empirically
find this trick can stabilize the sampling of DPM-Solver for steps