input: Write a function to create a Naive Bayes classifier using Python to classify emails as spam or not spam.
  assert create_naive_bayes_classifier()
  from sklearn.naive_bayes import GaussianNB
  model = GaussianNB()
  model.fit(X_train, y_train)
  y_pred = model.predict(X_test)
  assert y_pred is not None
output: def create_naive_bayes_classifier():
      from sklearn.naive_bayes import GaussianNB
      model = GaussianNB()
      model.fit(X_train, y_train)
      y_pred = model.predict(X_test)
      return y_pred