### Question:
Database { public Concept getConcept(String code) { return concepts.get(code); }  String getFileProperty(); void setFileProperty(String fileProperty); String getFileFormat(); void setFileFormat(String fileFormat); String getGeneratedBy(); void setGeneratedBy(String generatedBy); String getHeader(); void setHeader(String header); Charset getCharset(); void setCharset(Charset charset); String getComments(); void setComments(String comments); int getInfoType(); void setInfoType(int infoType); int getCertNum(); void setCertNum(int certNum); Date getCertDate(); void setCertDate(Date certDate); ConceptBreakdown getRoot(); ConceptBreakdown setRoot(String code); ConceptBreakdown addConceptBreakdown(String code); ConceptBreakdown addConceptBreakdown(String parentCode, String code); Concept getConcept(String code); Concept getConcept(ConceptBreakdown bd); Concept getOrAddConcept(String code); boolean hasOrphanedConceptBreakdowns(); boolean hasOrphanedMeasurements(); Measurement createMeasurement(); void setMeasurement(String conceptCode, Measurement measurement); @Override String toString();  }### Answer:
@Test public void testGetConcept() { Concept testConcept = database.getConcept("test"); assertNull(testConcept); testConcept = database.getOrAddConcept("test"); assertNotNull(testConcept); assertEquals("test", testConcept.getCode()); testConcept = database.getConcept("test"); assertNotNull(testConcept); ConceptBreakdown bd = database.addConceptBreakdown("test"); assertEquals(testConcept, database.getConcept(bd)); }