func (check *Checker) isTerminating(s syntax.Stmt, label string) bool {
	switch s := s.(type) {
	default:
		panic("unreachable")

	case *syntax.DeclStmt, *syntax.EmptyStmt, *syntax.SendStmt,
		*syntax.AssignStmt, *syntax.CallStmt:
		// no chance

	case *syntax.LabeledStmt:
		return check.isTerminating(s.Stmt, s.Label.Value)

	case *syntax.ExprStmt:
		// calling the predeclared (possibly parenthesized) panic() function is terminating

  EventListener.Factory {
  private var startNs: Long? = null

  override fun create(call: Call): EventListener = this

  override fun callStart(call: Call) {
    startNs = System.nanoTime()

    logWithTime("callStart: ${call.request()}")

    delegate.callStart(call)
  }

  override fun proxySelectStart(
    call: Call,
    url: HttpUrl,
  ) {
    logWithTime("proxySelectStart: $url")

      long nowNanos = System.nanoTime();
      if (name.equals("callStart")) {
        callStartNanos = nowNanos;
      }
      long elapsedNanos = nowNanos - callStartNanos;
      System.out.printf("%.3f %s%n", elapsedNanos / 1000000000d, name);
    }

    @Override public void callStart(Call call) {
      printEvent("callStart");
    }

    @Override public void proxySelectStart(Call call, HttpUrl url) {

    }

    // Observed Events are variable
    // JDK 14
    // CallStart, ProxySelectStart, ProxySelectEnd, DnsStart, DnsEnd, ConnectStart, SecureConnectStart,
    // SecureConnectEnd, ConnectEnd, ConnectionAcquired, RequestHeadersStart, RequestHeadersEnd,
    // ResponseFailed, ConnectionReleased, CallFailed
    // JDK 8
    // CallStart, ProxySelectStart, ProxySelectEnd, DnsStart, DnsEnd, ConnectStart, SecureConnectStart,

      mutableListOf<String>().apply {
        add("CallStart")
        if (connectionType != H2) {
          addAll(listOf("ConnectStart", "ConnectEnd"))
        }
        addAll(listOf("ConnectionAcquired", "ConnectionReleased", "CallEnd"))
      }

    assertThat(events2).isEqualTo(expectedEvents2)
  }

  private fun isConnectionEvent(it: CallEvent?) =
    it is CallStart ||
      it is CallEnd ||

  override fun connectionReleased(
    call: Call,
    connection: Connection,
  ) = logEvent(ConnectionReleased(System.nanoTime(), call, connection))

  override fun callStart(call: Call) = logEvent(CallStart(System.nanoTime(), call))

  override fun requestHeadersStart(call: Call) = logEvent(RequestHeadersStart(System.nanoTime(), call))

  override fun requestHeadersEnd(
    call: Call,

   *
   * This will be invoked only once for a single [Call]. Retries of different routes or redirects
   * will be handled within the boundaries of a single [callStart] and [callEnd]/[callFailed] pair.
   */
  open fun callStart(call: Call) {
  }

  /**
   * Invoked prior to a proxy selection.
   *
   * This will be invoked for route selection regardless of whether the client

  }

  data class CallStart(
    override val timestampNs: Long,
    override val call: Call,
  ) : CallEvent()

  data class CallEnd(
    override val timestampNs: Long,
    override val call: Call,
  ) : CallEvent() {
    override fun closes(event: CallEvent): Boolean = event is CallStart && call == event.call
  }

  data class CallFailed(

		// case *LabeledStmt:
		// case *BlockStmt:
		// case *ExprStmt:
		case *SendStmt:
			m = n.Chan
		// case *DeclStmt:
		case *AssignStmt:
			m = n.Lhs
		// case *BranchStmt:
		// case *CallStmt:
		// case *ReturnStmt:
		// case *IfStmt:
		// case *ForStmt:
		// case *SwitchStmt:
		// case *SelectStmt:

		// helper nodes
		case *RangeClause:
			if n.Lhs != nil {
				m = n.Lhs
				continue

    }

    @Override public void proxySelectEnd(Call call, HttpUrl url, List<Proxy> proxies) {
      printEvent("proxySelectEnd");
    }

    @Override public void callStart(Call call) {
      printEvent("callStart");
    }

    @Override public void dnsStart(Call call, String domainName) {
      printEvent("dnsStart");
    }