### Question:
FileSystemModel implements TreeModel { @Override public void valueForPathChanged(final TreePath path, final Object value) { File oldFile = (File) path.getLastPathComponent(); String fileParentPath = oldFile.getParent(); String newFileName = (String) value; File targetFile = new File(fileParentPath, newFileName); oldFile.renameTo(targetFile); File parent = new File(fileParentPath); int[] changedChildrenIndices = {getIndexOfChild(parent, targetFile)}; Object[] changedChildren = {targetFile}; fireTreeNodesChanged(path.getParentPath(), changedChildrenIndices, changedChildren); } FileSystemModel(final File rootDirectory); @Override Object getRoot(); @Override Object getChild(final Object parent, final int index); @Override int getChildCount(final Object parent); @Override boolean isLeaf(final Object node); @Override int getIndexOfChild(final Object parent, final Object child); @Override void valueForPathChanged(final TreePath path, final Object value); @Override void addTreeModelListener(final TreeModelListener listener); @Override void removeTreeModelListener(final TreeModelListener listener);  }### Answer:
@Test public void testValueForPathChanged() { System.out.println("valueForPathChanged"); TreePath path = null; Object value = null; FileSystemModel instance = null; }