code: def prepare_scores(scores):
      """
      Alter the scores matrix to avoid self loops and handle the root
      """
      # prevent self-loops, set up the root location
      np.fill_diagonal(scores, -float("inf"))  # prevent self-loops
      scores[0] = -float("inf")
      scores[0, 0] = 0
  
imports: import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: prepare_scores(scores) without return types