### Question:
MetricsProcessor extends ApiDataListener { public MetricsData getMetricsData(int id) { MetricsContext context = metricsContexts.get(id); if (context != null) { return context.getMetricsData(); } return null; } private  MetricsProcessor(); int addContext(); static MetricsProcessor getInstance(); @Override void processData(List<String> jsonData); boolean removeContext(int id); MetricsData getMetricsData(int id); boolean resetMetricsData(int id); Integer[] getContextIds(); String getEnvironment();  }### Answer:
@Test public void testInitialState() { MetricsData md = mp.getMetricsData(0); assertNull("Expected no contexts but found one", md); md = mp.getMetricsData(1); assertNull("Context 1 should not exist", md); }