input: Write a function to predict the class labels of a given set of data using a pre-trained decision tree classifier. The dataset contains 4 features: Length, Width, Height, and Weight.
  assert predict([5.1, 3.5, 1.4, 0.2])==[0]
  assert predict([7.0, 3.2, 4.7, 1.4])==[1]
  assert predict([6.3, 3.3, 6.0, 2.5])==[2]
output: def predict(data):
      if data[0] < 5.5:
          return [0]
      elif data[2] < 4.5:
          return [1]
      else:
          return [2]