code: def get_standardize_f(train):
      mu = np.mean(train, axis=0)
      std = np.std(train, axis=0)
      return lambda x: (x - mu) / std
  
imports: import math
  import warnings
  import click
  import numpy
  import pandas
  from sklearn.metrics import mean_squared_error
  from sklearn.model_selection import train_test_split
  from tensorflow import keras
  from tensorflow.keras.callbacks import Callback
  from tensorflow.keras.layers import Dense, Lambda
  from tensorflow.keras.models import Sequential
  from tensorflow.keras.optimizers import SGD
  import mlflow
  from mlflow.models import infer_signature
label_desc: Use image node_id 2 for calling a global function with example usage: get_standardize_f(train) and returns: function