### Question:
PerAlleleCollection { public Set<Allele> getAltAlleles(){ return(altAlleleValueMap.keySet()); } private  PerAlleleCollection(boolean altOnly); static PerAlleleCollection createPerAltAlleleCollection(); static PerAlleleCollection createPerRefAndAltAlleleCollection(); void set(Allele allele, X newValue); void setRef(Allele refAllele, X newValue); void setAlt(Allele altAllele, X newValue); X get(Allele allele); X getRef(); X getAlt(Allele allele); Set<Allele> getAltAlleles();  }### Answer:
@Test public void testGetAltAlleles() throws Exception { PerAlleleCollection<Integer> alleleCounts = PerAlleleCollection.createPerAltAlleleCollection(); Allele altA = Allele.create("A", false); Allele altC = Allele.create("C", false); Allele altG = Allele.create("G", false); Allele altT = Allele.create("T", false); Allele[] altAlleles = {altA, altC, altG, altT}; for (Allele altAllele : altAlleles ) { alleleCounts.set(altAllele, 3); } for (Allele altAllele : altAlleles ) { assertTrue(alleleCounts.getAltAlleles().contains(altAllele)); } assertFalse(alleleCounts.getAltAlleles().contains(Allele.create("A", true))); }