code: def second_walk(v, m=0, depth=0, min=None):
      v.x += m
      v.y = depth
  
      if min is None or v.x < min:
          min = v.x
  
      for w in v.children:
          min = second_walk(w, m + v.mod, depth + 1, min)
  
      return min
  
file_path: scikit-learn/sklearn/tree/_reingold_tilford.py
imports: import numpy
label_desc: Use image node_id 8 for calling a global function with example usage: second_walk(v, m, depth, min) and returns: min