input: Write a function to determine if it is possible to get an array sorted in non-decreasing order by performing any number of intersect operation on the given arrays. If it is possible return the common elements else return an empty list. If the given array is empty then return an empty list.
  def common_elements(list1, list2): 
      common_list=[]
      for element in list1: 
          if element in list2: 
              common_list.append(element) 
      return common_list
      
  assert common_elements([1, 2, 3, 4, 8], [2, 6, 8, 10])==[2, 8]
  assert common_elements([1, 2, 3, 4], [5, 6, 7, 8])==[]
  assert common_elements([1, 2, 3], [1, 2, 3])==[1, 2, 3]
  assert common_elements([1, 3, 5], [2, 4, 6])==[]
  assert common_elements([], [1, 2, 3])==[]
output: def common_elements(list1, list2): 
      common_list = []
      for element in list1: 
          if element in list2: 
              common_list.append(element) 
      return common_list