code: def initialize(label):
      init_score = label.create_frame()
      mean_score = float(label.mean())
      init_score["score"] = mean_score
      return init_score, mean_score
  
imports: import numpy
  import pandas
  import torch
  from fate.arch.dataframe import DataFrame
  from scipy.special import expit
  from fate.ml.utils.predict_tools import BINARY, MULTI, REGRESSION
label_desc: Use image node_id 1 for calling the L2Loss obj's underlying member method code with example usage: obj.initialize(label) and returns: init_score,  mean_score