input: from sklearn.naive_bayes import GaussianNB
  
  def train_naive_bayes(X_train, y_train, X_test):
      """ Train a Naive Bayes classifier using GaussianNB from sklearn and return the predicted outputs for the test data.
      >>> train_naive_bayes([[1, 2], [3, 4]], [0, 1], [[1, 1], [4, 4]])
      array([0, 1])
      """
      model = GaussianNB()
      model.fit(X_train, y_train)
      return model.predict(X_test)
output:     model = GaussianNB()
      model.fit(X_train, y_train)
      return model.predict(X_test)