tr.CloseIdleConnections()
	if !tr.IsIdleForTesting() {
		t.Error("should be idle after CloseIdleConnections")
	}
	wantIdle("after close idle", 0)
	if tr.PutIdleTestConn("http", "example.com") {
		t.Fatal("put didn't fail")
	}
	wantIdle("after second put", 0)

	tr.QueueForIdleConnForTesting() // should toggle the transport out of idle mode
	if tr.IsIdleForTesting() {