input: Write a function to shuffle an array of integers using the Python random library's shuffle method. The function should take an array as input, shuffle it in place, and return the shuffled array.
  
  assert shuffle([1, 5, 9, 4, 2])==[1, 5, 9, 4, 2]
  assert shuffle([3, 2, 1, 5, 4])==[3, 2, 1, 5, 4]
  assert shuffle([10, 20, 30, 40, 50])==[10, 20 ,30, 40 ,50]
  assert shuffle([])==[]
  assert shuffle([7, 8, 9])==[7, 8, 9]
output: import random
  
  def shuffle(arr):
      random.shuffle(arr)
      return arr