Pedigree { public static Pedigree empty() { return EMPTY; } private  Pedigree(Collection<Individual> individuals); static Pedigree of(Collection<Individual> individuals); static Pedigree of(Individual... individuals); static Pedigree justProband(String id); static Pedigree empty(); @JsonIgnore boolean containsId(String id); @JsonIgnore Individual getIndividualById(String individualId); Set<Individual> getIndividuals(); @JsonIgnore Set<String> getIdentifiers(); @JsonIgnore int size(); @JsonIgnore boolean isEmpty(); @JsonIgnore int numFamilies(); @Override boolean equals(Object o); @Override int hashCode(); @Override String toString();  }
@Test public void testEmpty() { Pedigree instance = Pedigree.empty(); assertThat(instance.getIndividuals().isEmpty(), is(true)); }