### Question:
GeneIdentifier implements Comparable<GeneIdentifier> { public String getGeneSymbol() { return geneSymbol; } private  GeneIdentifier(Builder builder); String getGeneId(); String getGeneSymbol(); String getHgncId(); String getHgncSymbol(); String getEntrezId(); @JsonIgnore Integer getEntrezIdAsInteger(); boolean hasEntrezId(); String getEnsemblId(); String getUcscId(); int compareTo(GeneIdentifier otherGeneIdentifier); static int compare(GeneIdentifier g1, GeneIdentifier g2); @Override boolean equals(Object o); @Override int hashCode(); @Override String toString(); static Builder builder(); static final String EMPTY_FIELD; }### Answer:
@Test public void getGeneSymbol() { assertThat(EMPTY_GENE_IDENTIFIER.getGeneSymbol(), equalTo(GeneIdentifier.EMPTY_FIELD)); GeneIdentifier instance = GeneIdentifier.builder() .geneSymbol("ABC1") .build(); assertThat(instance.getGeneSymbol(), equalTo("ABC1")); }