FractionList implements org.wildfly.swarm.tools.FractionList { public static FractionList get() { return INSTANCE.updateAndGet(old -> old != null ? old : new FractionList()); } private  FractionList(); static FractionList get(); @Override Collection<FractionDescriptor> getFractionDescriptors(); @Override FractionDescriptor getFractionDescriptor(final String groupId, final String artifactId); @Override Map<String, FractionDescriptor> getPackageSpecs();  }
@Test public void testMultipleGets() throws IOException { FractionList l1 = FractionList.get(); FractionList l2 = FractionList.get(); FractionList l3 = FractionList.get(); assertThat(l1).isNotNull(); assertThat(l1).isSameAs(l2); assertThat(l2).isSameAs(l3); }