### Question:
StackMatrixService { public StackMatrixV4Response getStackMatrix(String platform) throws CloudbreakImageCatalogException { return getStackMatrix(0L, platform, null); }  StackMatrixV4Response getStackMatrix(String platform); StackMatrixV4Response getStackMatrix(Long workspaceId, String platform, String imageCatalogName); Set<String> getSupportedOperatingSystems(Long workspaceId, String clusterVersion, String platform, String imageCatalogName);  }### Answer:
@Test public void getStackMatrixWithoutAmbari() throws Exception { setupStackEntries(); when(converterUtil.convert(any(RepositoryInfo.class), eq(ClouderaManagerInfoV4Response.class))).thenReturn(new ClouderaManagerInfoV4Response()); StackMatrixV4Response stackMatrixV4Response = stackMatrixService.getStackMatrix(WORKSPACE_ID, PLATFORM, IMAGE_CATALOG_NAME); assertEquals(1L, stackMatrixV4Response.getCdh().size()); assertEquals("6.1.0-1.cdh6.1.0.p0.770702", stackMatrixV4Response.getCdh().get("6.1.0").getVersion()); assertNull(stackMatrixV4Response.getCdh().get("6.1.0").getClouderaManager().getRepository()); assertNull(stackMatrixV4Response.getCdh().get("6.1.0").getClouderaManager().getVersion()); }