docstr: Discretize the chain into a list of chains according to unit size.
code: def discretize_all(self, unit: int):
      """Discretize the chain into a list of chains according to unit size."""
      discretizer = lambda val: math.ceil(val / unit)
      self.x = tree_map(discretizer, self.x)
      self.xbar = tree_map(discretizer, self.xbar)
      self.ftmp = tree_map(discretizer, self.ftmp)
      self.btmp = tree_map(discretizer, self.btmp)
  
imports: import math
  from abc import ABC
  from typing import List
  from torch.utils._pytree import tree_map
label_desc: Use image node_id 5 for calling the Chain obj's underlying member method code with example usage: obj.discretize_all(unit) without return types