input: Write a python function to load a pre-trained model from a given file path using pickle and predict the class of a given text input.
  assert classify_text("This is a test of a text classification program.", "pre_trained_model.pkl") == expected_output
  assert classify_text("Another example sentence for classification.", "pre_trained_model.pkl") == another_expected_output
output: import pickle
  
  def classify_text(text, model_path):
      with open(model_path, 'rb') as file:
          model = pickle.load(file)
      return model.predict([text])[0]