parameters: (self, head)
return_statement: return quick
docstring: :type head: ListNode
          :rtype: ListNode
docstring_summary: :type head: ListNode
          :rtype: ListNode
docstring_tokens: : type head : ListNode : rtype : ListNode
function: def detectCycle(self, head):
          """
          :type head: ListNode
          :rtype: ListNode
          """
          
          quick = head
          slow = head
          result = False
  
          while (quick is not None and quick.next is not None):
              quick = quick.next.next
              slow = slow.next
              if quick == slow:
                  result = True
                  break
  
          if not result:
              return None
  
          quick = head
          while (quick != slow):
              quick = quick.next
              slow = slow.next
  
          return quick
function_tokens: def detectCycle ( self , head ) : quick = head slow = head result = False while ( quick is not None and quick . next is not None ) : quick = quick . next . next slow = slow . next if quick == slow : result = True break if not result : return None quick = head while ( quick != slow ) : quick = quick . next slow = slow . next return quick