input: 
  def identify_author(samples: List[str], labels: List[str], test_size: float = 0.3) -> float:
      """ Develop a machine learning model to identify the author of a given article.
      The function uses a pipeline that includes TF-IDF vectorization and Gaussian Naive Bayes classification.
      It returns the accuracy score of the model on the test set.
      
      >>> identify_author(["sample 1 from AuthorA", "sample 2 from AuthorA", "sample 1 from AuthorB", "sample 2 from AuthorB"], ["AuthorA", "AuthorA", "AuthorB", "AuthorB"])
      1.0
      >>> identify_author(["sample 1 from AuthorA", "sample 2 from AuthorA", "sample 1 from AuthorB"], ["AuthorA", "AuthorA", "AuthorB"], test_size=0.5)
      0.0
      """
      from sklearn.feature_extraction.text import TfidfVectorizer
      from sklearn.naive_bayes import GaussianNB
      from sklearn.pipeline import Pipeline
      from sklearn.model_selection import train_test_split
  
      model = Pipeline([
          ('tfidf', TfidfVectorizer()),
          ('clf', GaussianNB())
      ])
  
      X_train, X_test, y_train, y_test = train_test_split(samples, labels, test_size=test_size)
      model.fit(X_train, y_train)
  
      score = model.score(X_test, y_test)
      return score
  
output:     from sklearn.feature_extraction.text import TfidfVectorizer
      from sklearn.naive_bayes import GaussianNB
      from sklearn.pipeline import Pipeline
      from sklearn.model_selection import train_test_split
  
      model = Pipeline([
          ('tfidf', TfidfVectorizer()),
          ('clf', GaussianNB())
      ])
  
      X_train, X_test, y_train, y_test = train_test_split(samples, labels, test_size=test_size)
      model.fit(X_train, y_train)
  
      score = model.score(X_test, y_test)
      return score