protected final String baseUrl() {
        return "h2c://127.0.0.1:" + server.activeLocalPort(SessionProtocol.HTTP);
    }
The base for {@link WithDuplicator} and {@link WithoutDuplicator} microbenchmarks.
benchmarks/jmh/src/jmh/java/com/linecorp/armeria/core/client/retry/RetryingClientBase.java