code: def annealing_cos(start:Number, end:Number, pct:float)->Number:
      "Cosine anneal from `start` to `end` as pct goes from 0.0 to 1.0."
      cos_out = np.cos(np.pi * pct) + 1
      return end + (start-end)/2 * cos_ouf annealing_cos(start:Number, end:Number, pct:float)->Number:
      "Cosine anneal from `start` to `end` as pct goes from 0.0 to 1.0."
      cos_out = np.cos(np.pi * pct) + 1
      return end + (start-end)/2 * cos_out
docs: Cosine anneal from `start` to `end` as pct goes from 0.0 to 1.0.