### Question:
TreatmentDefinition extends AbstractEntity implements Comparable<TreatmentDefinition> { public SortedSet<Category> getContents() { return d_contents; } TreatmentDefinition(Category category);  TreatmentDefinition(Collection<Category> contents);  TreatmentDefinition(); static TreatmentDefinition createTrivial(Collection<Drug> drugs); static TreatmentDefinition createTrivial(Drug drug); @Override Set<? extends Entity> getDependencies(); SortedSet<Category> getContents(); String getLabel(); @Override boolean equals(Object o); @Override boolean deepEquals(Entity o); @Override int hashCode(); @Override int compareTo(TreatmentDefinition o); @Override String toString(); boolean match(TreatmentActivity act); boolean match(Study study, Arm arm);  }### Answer:
@Test public void testNoArgConstruction() { assertEquals(Collections.emptySet(), d_empty.getContents()); }
@Test public void testDrugConstruction() { assertEquals(Collections.singleton(d_singleCategory), d_single.getContents()); }
@Test public void testCollectionConstruction() { assertEquals(new HashSet<Category>(d_multiCategory), d_multi.getContents()); }