code: def m4n2_2d_greedy(mat, density):
      return mn_2d_greedy(mat, 4, 2)
  
file_path: apex/apex/contrib/sparsity/sparse_masklib.py
imports: import sys
  import torch
  import numpy
  import collections
  from itertools import permutations
label_desc: Use image node_id 7 for calling a global function with example usage: m4n2_2d_greedy(mat, density) and returns: mn_2d_greedy