code: def _append_contraction_marks_sub(Z, iv, i, n, contraction_marks):
      if i >= n:
          contraction_marks.append((iv, Z[i - n, 2]))
          _append_contraction_marks_sub(
              Z, iv, int(Z[i - n, 0]), n, contraction_marks
          )
          _append_contraction_marks_sub(
              Z, iv, int(Z[i - n, 1]), n, contraction_marks
          )
  
imports: import warnings
  import bisect
  from collections import deque
  import numpy
  from .None import _hierarchy, _optimal_leaf_ordering
  import scipy.spatial.distance
  from scipy._lib._disjoint_set import DisjointSet
label_desc: Use image node_id 44 for calling a global function with example usage: _append_contraction_marks_sub(Z, iv, i, n, contraction_marks) without return types