input: 
  from sklearn.naive_bayes import GaussianNB
  
  def naive_bayes_email_classifier(X_train, y_train, X_test):
      """
      Construct a naive bayes classifier to classify emails as spam or not spam.
      >>> naive_bayes_email_classifier(X_train, y_train, X_test)
      array([0, 1, 0, 1])
      """
      # Create a Gaussian Classifier
      model = GaussianNB()
      
      # Train the model using the training sets 
      model.fit(X_train, y_train)
      
      # Predict Output 
      y_pred = model.predict(X_test)
      
      return y_pred
  
output:     # Create a Gaussian Classifier
      model = GaussianNB()
      
      # Train the model using the training sets 
      model.fit(X_train, y_train)
      
      # Predict Output 
      y_pred = model.predict(X_test)
      
      return y_pred