### Question:
QualifiedName { public static QualifiedName toQualifiedName(TDefinitions model, String qName) { if (qName == null || qName.isEmpty()) { return null; } if (qName.startsWith(DMNVersion.LATEST.getFeelPrefix() + ".")) { String prefix = DMNVersion.LATEST.getFeelPrefix(); String localPart = qName.substring(qName.indexOf('.') + 1); return new QualifiedName(prefix, localPart); } if (model == null) { return new QualifiedName(null, qName); } else { for (TImport import_: model.getImport()) { String importName = import_.getName(); if (qName.startsWith(importName + '.')) { String localPart = qName.substring(qName.indexOf('.') + 1); return new QualifiedName(importName, localPart); } } return new QualifiedName(null, qName); } } private  QualifiedName(String namespace, String localPart); static QualifiedName toQualifiedName(TDefinitions model, String qName); String getNamespace(); String getLocalPart(); @Override String toString();  }### Answer:
@Test public void testConstructorWithNullString() { QualifiedName qualifiedName = QualifiedName.toQualifiedName(null, null); assertNull(qualifiedName); }
@Test public void testConstructorWithEmptyString() { QualifiedName qualifiedName = QualifiedName.toQualifiedName(null, ""); assertNull(qualifiedName); }