input: Write a function to reverse a given list. The function should return the reversed list as its output.
  def reverse_list(list): 
      return list[::-1]
  
  assert reverse_list([1,2,3,4,5])==[5,4,3,2,1]
  assert reverse_list([9,8,7,6])==[6,7,8,9]
  assert reverse_list([])==[]
  assert reverse_list([4,3,2,1])==[1,2,3,4]
  assert reverse_list(['a','b','c'])==['c','b','a']
output: def reverse_list(list): 
      return list[::-1]