### Question:
FHIRExtractors { public static Identifier parseIDFromQueryParam(String queryParam) { final Pair<String, String> stringPair = parseTag(queryParam); final Identifier identifier = new Identifier(); String system = stringPair.getLeft(); if (system.endsWith("\\")) { system = system.substring(0, system.length() - 1); } identifier.setSystem(system); identifier.setValue(stringPair.getRight()); return identifier; } private  FHIRExtractors(); static String getProviderNPI(Practitioner provider); static String getPatientMBI(Patient patient); static String getPatientBeneId(Patient patient); static UUID getEntityUUID(String idString); static Provenance.ProvenanceAgentComponent getProvenancePerformer(Provenance provenance); static Identifier parseIDFromQueryParam(String queryParam); static Pair<String, String> parseTag(String tag); static Identifier findMatchingIdentifier(List<Identifier> identifiers, DPCIdentifierSystem system); static String getOrganizationID(IBaseResource resource); static String getAttributedNPI(Group group);  }### Answer:
@Test void testIDExtraction() { final Identifier identifier = parseIDFromQueryParam(String.format("%s|%s", DPCIdentifierSystem.DPC.getSystem(), "hello")); assertAll(() -> assertEquals(DPCIdentifierSystem.DPC.getSystem(), identifier.getSystem(), "Should have correct system"), () -> assertEquals("hello", identifier.getValue(), "Should have correct value")); final Identifier emptyValue = parseIDFromQueryParam(String.format("%s|%s", DPCIdentifierSystem.HICN.getSystem(), "")); assertAll(() -> assertEquals(DPCIdentifierSystem.HICN.getSystem(), emptyValue.getSystem(), "Should have correct system"), () -> assertNull(emptyValue.getValue(), "Should have empty value")); final Identifier trailingSystem = parseIDFromQueryParam(String.format("%s\\|%s", DPCIdentifierSystem.HICN.getSystem(), "nada9")); assertAll(() -> assertEquals(DPCIdentifierSystem.HICN.getSystem(), trailingSystem.getSystem(), "Should have correct system"), () -> assertEquals("nada9", trailingSystem.getValue(), "Should have empty value")); }