code: def f_default(self, t, y):
      raise RuntimeError(
          "Method `f` has not been provided, but is required for this method."
      )
  
imports: import abc
  import torch
  from torch import nn
  from .None import misc
  from ..settings import NOISE_TYPES, SDE_TYPES
  from ..types import Tensor
label_desc: Use image node_id 2 for calling the ForwardSDE obj's underlying member method code with example usage: obj.f_default(t, y) without return types