input: def NaiveBayesClassifier():
      """Construct a naive bayes classifier using python to classify emails as spam or not spam.
      >>> # Example usage with training and test data (X_train, y_train, X_test)
      >>> from sklearn.naive_bayes import GaussianNB
      >>> model = GaussianNB()
      >>> model.fit(X_train, y_train)
      >>> y_pred = model.predict(X_test)
      >>> print(y_pred) # Output depends on the data used for training and testing
      """
output:     from sklearn.naive_bayes import GaussianNB
      model = GaussianNB()
      return model