input: Write a function to generate a 3x3 numpy array filled with random integers ranging from 1 to 5 using the NumPy library. If the array is successfully generated, return the array itself; otherwise, return None.
  
  assert np.shape(generate_random_array()) == (3, 3)
  assert np.all(generate_random_array() >= 1) and np.all(generate_random_array() <= 5)
  assert generate_random_array() is not None
output: import numpy as np
  
  def generate_random_array():
      try:
          return np.random.randint(1, 6, (3, 3))
      except:
          return None