@Test
    public void hystrixCommand_toObservable() throws Exception {
        hystrixCommandTestRunner.toObservable();

        PluginTestVerifier verifier = PluginTestVerifierHolder.getInstance();
        verifier.printCache();
        verifier.ignoreServiceType("RX_JAVA", "RX_JAVA_INTERNAL");

        HystrixTestHelper.verifyHystrixMetricsInitialization(verifier, SayHelloCommand.class.getSimpleName(), COMMAND_GROUP);

        verifier.verifyTrace(event("HYSTRIX_COMMAND", "com.netflix.hystrix.AbstractCommand.toObservable()", annotation("hystrix.command", SayHelloCommand.class.getSimpleName())));
        verifier.verifyTrace(event("HYSTRIX_COMMAND_INTERNAL", "com.netflix.hystrix.AbstractCommand$HystrixObservableTimeoutOperator.call(rx.Subscriber)"));
        verifier.verifyTrace(event("HYSTRIX_COMMAND_INTERNAL", "com.netflix.hystrix.strategy.concurrency.HystrixContextScheduler$HystrixContextSchedulerWorker.schedule(rx.functions.Action0)"));

        // execution
        verifier.verifyTrace(event("ASYNC", "Asynchronous Invocation"));
        Method getExecutionObservable = HystrixCommand.class.getDeclaredMethod("getExecutionObservable");
        verifier.verifyTrace(event("HYSTRIX_COMMAND_INTERNAL", getExecutionObservable));
        Method helloMethod = HelloRepository.class.getDeclaredMethod("hello", String.class);
        verifier.verifyTrace(event("INTERNAL_METHOD", helloMethod));

        verifier.verifyTraceCount(0);
    }
Integration test for hystrix-core 1.4.0 to 1.5.2 traces the following :
<p>
<tt>HystrixCommand.execute()</tt><br/>
<tt>HystrixCommand.observe()</tt>
<tt>HystrixCommand.toObservable()</tt>
<p>
Additionally, the cause of fallback should be traced via AbstractCommand.getFallbackOrThrowException() invocation.

@author Jiaqi Feng
@author HyunGil Jeong
agent-module/plugins-it/hystrix-it/src/test/java/com/navercorp/pinpoint/it/plugin/hystrix/HystrixCommand_1_4_0_to_1_5_2_IT.java