he original paper as being required before
PLMS steps.   set_alpha_to_one (bool, defaults to False) —
Each diffusion step uses the alphas product value at that step and at the previous one. For the final step
there is no previous alpha. When this option is True the previous alpha product is fixed to 1,
otherwise it uses the alpha value at step 0.   prediction_type (str, defaults to epsilon, optional) —
Prediction type of the scheduler function;