comefrom: <qiyuangong>083_Remove_Duplicates_from_Sorted_List_1.py
code: def deleteDuplicates( head):
      if head is None:
          return None
      pos = head
      while pos is not None and pos.next is not None:
          if pos.val == pos.next.val:
              pos.next = pos.next.next
          else:
              pos = pos.next
      return head
masked: def sample_funcname ( var_0 ) :
      if var_0 is None :
          return None
      var_2 = var_0
      while var_2 is not None and var_2.next is not None :
          if var_2.val == var_2.next.val :
              var_2.next = var_2.next.next
          else :
              var_2 = var_2.next
      return var_0
  