Bug 51648 ClassCastException after aborted local rename
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/correction/LinkedNamesAssistProposal.java
import org.eclipse.swt.graphics.Point;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DocumentEvent;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.contentassist.ICompletionProposalExtension2;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.core.dom.SimpleName;
import org.eclipse.jdt.ui.text.java.IJavaCompletionProposal;
import org.eclipse.jdt.internal.corext.dom.LinkedNodeFinder;
import org.eclipse.jdt.internal.corext.dom.NodeFinder;
import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.JavaPluginImages;
import org.eclipse.jdt.internal.ui.text.link.LinkedEnvironment;
import org.eclipse.jdt.internal.ui.text.link.LinkedPositionGroup;
import org.eclipse.jdt.internal.ui.text.link.LinkedUIControl;
/**
 * A template proposal.
 */
public class LinkedNamesAssistProposal implements IJavaCompletionProposal, ICompletionProposalExtension2 {
	private SimpleName fNode;
	private IRegion fSelectedRegion; 
	private ICompilationUnit fCompilationUnit;
			
	public LinkedNamesAssistProposal(ICompilationUnit cu, SimpleName node) {