code: def test_norm_freq_str():
      assert norm_freq_str(to_offset("Y").name) == "A"
      assert norm_freq_str(to_offset("YS").name) == "A"
      assert norm_freq_str(to_offset("A").name) == "A"
      assert norm_freq_str(to_offset("AS").name) == "A"
  
      assert norm_freq_str(to_offset("Q").name) == "Q"
      assert norm_freq_str(to_offset("QS").name) == "Q"
  
      assert norm_freq_str(to_offset("M").name) == "M"
      assert norm_freq_str(to_offset("MS").name) == "M"
  
      assert norm_freq_str(to_offset("S").name) == "S"
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_norm_freq_str() without return types