Pedigree { @JsonIgnore public boolean isEmpty() { return individuals.isEmpty(); } 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 testIsEmpty() { assertThat(Pedigree.empty().isEmpty(), is(true)); assertThat(Pedigree.justProband("Nemo").isEmpty(), is(false)); }