code: def valid_callbacks(cls):
      return super(
          RKAdaptiveStepsizeODESolver, cls
      ).valid_callbacks() | {
          "callback_step",
          "callback_accept_step",
          "callback_reject_step",
      }
  
imports: import bisect
  import collections
  import torch
  from .event_handling import find_event
  from .interp import _interp_evaluate, _interp_fit
  from .misc import _compute_error_ratio, _select_initial_step, _optimal_step_size
  from .misc import Perturb
  from .solvers import AdaptiveStepsizeEventODESolver
label_desc: Use image node_id 2 for calling the RKAdaptiveStepsizeODESolver obj's underlying member method code with example usage: obj.valid_callbacks(cls) and returns: unknown