code: def _step_func(self, func, t0, dt, t1, y0):
      f0 = func(
          t0, y0, perturb=Perturb.NEXT if self.perturb else Perturb.NONE
      )
      return dt * f0, f0
  
file_path: torchdiffeq/torchdiffeq/_impl/fixed_grid.py
imports: from .solvers import FixedGridODESolver
  from .rk_common import rk4_alt_step_func, rk3_step_func
  from .misc import Perturb
label_desc: Use image node_id 1 for calling the Euler obj's underlying member method code with example usage: obj._step_func(func, t0, dt, t1, y0) and returns: unknown,  f0