class_docstr: Calculate the Munkres solution to the classical assignment problem.
  See the module documentation for usage.
docstr: Find a zero (Z) in the resulting matrix. If there is no starred
  zero in its row or column, star Z. Repeat for each element in the
  matrix. Go to Step 3.
docstr_tok: ["Find","a","zero","(","Z",")","in","the","resulting","matrix",".","If","there","is","no","starred","zero","in","its","row","or","column",",","star","Z.","Repeat","for","each","element","in","the","matrix",".","Go","to","Step","3","."]
code: def __step2(self):
      """
      Find a zero (Z) in the resulting matrix. If there is no starred
      zero in its row or column, star Z. Repeat for each element in the
      matrix. Go to Step 3.
      """
      n = self.n
      for i in range(n):
          for j in range(n):
              if (
                  (self.C[i][j] == 0)
                  and (not self.col_covered[j])
                  and (not self.row_covered[i])
              ):
                  self.marked[i][j] = 1
                  self.col_covered[j] = True
                  self.row_covered[i] = True
  
      self.__clear_covers()
      return 3
  
imports: import sys
label_desc: Use image node_id 8 for calling the Munkres obj's underlying member method code with example usage: obj.__step2() and returns: int