### Question:
DatasetImporterForDBatVir extends DatasetImporterWithListener { static String extractFirstPubMedReferenceId(String pubMed) { Pattern compile = Pattern.compile("(.*)(nih.gov/pubmed/)(\\d+)(.*)"); Matcher matcher = compile.matcher(pubMed); String referenceId = ""; if (matcher.find()) { String pubmedId = matcher.group(3); referenceId = "http: } return referenceId; } DatasetImporterForDBatVir(ParserFactory parserFactory, NodeFactory nodeFactory); static String scrubReferenceCitation(String refs); @Override void importStudy(); int getTotalCount(); static void parseInteractions(InputStream pageStream, InteractionListener interactionListener); static ObjectMapper getLenientObjectMapper();  }### Answer:
@Test public void extactPubmed() { String pubMed = "<a href='http: String referenceId = DatasetImporterForDBatVir.extractFirstPubMedReferenceId(pubMed); assertThat(referenceId, Is.is("http: }