[Demonstration 1]

[Buggy Method]
public void addChild(File child) {
    child.setParent(child);
    children.add(child);
}

[Buggy Hunk]
child.setParent(child);

[Patch]
child.setParent(this);

[Demonstration 2]

[Buggy Method]
private boolean isTypeDefinition(Node rhs) {
    return rhs.isClass() || rhs.getType() == Token.INTERFACE;
}

[Buggy Hunk]
return rhs.isClass() || rhs.getType() == Token.INTERFACE;

[Patch]
return rhs.isClass() || rhs.getToken() == Token.INTERFACE;

[Demonstration 3]

[Buggy Method]
@Override
public void exportNodes(RootNode source, RootNode rootNode) {
    for (Node n : source.getScenes()) {
        NodeExporter exporter = nodeExporters.get(n.getType());
        Node export = null;
        if (exporter != null) {
            export = exporter.exportNode(n, rootNode);
        } else {
            export = new Node(n);
        }
        for (Node child : n.getChildren()) {
            export.addChild(exportNode(child, rootNode));
        }
    }
}

[Buggy Hunk]
export = new Node(n);

[Patch]
throw new IllegalAccessError("Invalid node type: " + n.getType());