_steps must be None.    Sets the timesteps used for the diffusion chain (to be run before inference).  sigma_to_t  < source > ( sigmas: Union  ) → float or np.ndarray  Parameters   sigmas (float or np.ndarray) —
A single Karras sigma or an array of Karras sigmas.   Returns 
float or np.ndarray
  
A scaled input timestep or scaled input timestep array.
  Gets scaled timesteps from the Karras sigmas for input to the consistency model.  step  < so