comefrom: <qiyuangong>141_Linked_List_Cycle_3.py
code: def hasCycle( head):
      try:
          fast = head.next.next
          slow = head.next
      
          while fast != slow:
              fast = fast.next.next
              slow = slow.next
      
          return True
      except:
          return False
masked: def sample_funcname ( var_0 ) :
      try :
          var_2 = var_0.next.next
          var_3 = var_0.next
          while var_2 != var_3 :
              var_2 = var_2.next.next
              var_3 = var_3.next
          return True
      except :
          return False
  