### Question:
OpenTelemetry { public static Tracer getTracer(String instrumentationName) { return getTracerProvider().get(instrumentationName); } private  OpenTelemetry(); static TracerProvider getTracerProvider(); static Tracer getTracer(String instrumentationName); static Tracer getTracer(String instrumentationName, String instrumentationVersion); static MeterProvider getMeterProvider(); static Meter getMeter(String instrumentationName); static Meter getMeter(String instrumentationName, String instrumentationVersion); static BaggageManager getBaggageManager(); static ContextPropagators getPropagators(); static void setPropagators(ContextPropagators propagators);  }### Answer:
@Test void testTracerNotFound() { System.setProperty(TracerProviderFactory.class.getName(), "io.does.not.exists"); assertThrows(IllegalStateException.class, () -> OpenTelemetry.getTracer("testTracer")); }