### Question:
Icinga2PerformanceDataBuilder extends AbstractPerformanceDataBuilder implements Builder<List<String>> { @Override public List<String> build() { String performanceData = getTestSuitePerformanceData(testSuite); if (performanceData != null) { return Arrays.asList(StringUtils.split(performanceData)); } return Collections.emptyList(); }  @Override List<String> build();  }### Answer:
@Test public void testBuild() throws Exception { ReflectionTestUtils.setField(testling, "testSuite", new TestSuiteExampleBuilder().buildExample()); Iterator<String> it = testling.build().iterator(); assertEquals(it.next(), "suite__state=3;;;;"); assertRegExMatch(it.next(), "suite_UnitTest_\\d*=U;;;;"); assertEquals(it.next(), "c_001__state=0;;;;"); assertEquals(it.next(), "c_001__warning=4s;;;;"); assertEquals(it.next(), "c_001__critical=5s;;;;"); assertRegExMatch(it.next(), "c_001_UNIT_TEST_CASE_\\d*=3.00s;4;5;;"); assertEquals(it.next(), "s_001_001_step_for_unit_test=3.00s;4;;;"); assertFalse(it.hasNext()); }