Bug 9304 new class wizard: incorrect terminology used
1. new class wizard 2. press Add.. in interfaces 3. the dialog you see has a title 'Extended Interfaces Selection' this is incorrect - it should be 'Implemented Interfaces Selection' (this bug was pointed out on the wsad newsgroup)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/TypePage.java
int threshold= ImportOrganizePreferencePage.getImportNumberThreshold();			
		
		String lineDelimiter= null;	
		if (!isInnerClass) {
			lineDelimiter= System.getProperty("line.separator", "\n");
			
			String packStatement= pack.isDefaultPackage() ? "" : "package " + pack.getElementName() + ";" + lineDelimiter;
			ICompilationUnit parentCU= pack.createCompilationUnit(clName + ".java", packStatement, false, new SubProgressMonitor(monitor, 2)); 
			imports= new ImportsStructure(parentCU, prefOrder, threshold, false);
			
			String content= createTypeBody(imports, lineDelimiter, parentCU);
			createdType= parentCU.createType(content, null, false, new SubProgressMonitor(monitor, 3));
		} else {
			IType enclosingType= getEnclosingType();
			
			
			
			IType workingCopy= (IType) EditorUtility.getWorkingCopy(enclosingType);
			if (workingCopy != null) {
				enclosingType= workingCopy;
			}
			ICompilationUnit parentCU= enclosingType.getCompilationUnit();
			imports= new ImportsStructure(parentCU, prefOrder, threshold, true);
			
			lineDelimiter= StubUtility.getLineDelimiterUsed(enclosingType);
			String content= createTypeBody(imports, lineDelimiter, parentCU);
			IJavaElement[] elems= enclosingType.getChildren();
			IJavaElement sibling= elems.length > 0 ? elems[0] : null;
			
			createdType= enclosingType.createType(content, sibling, false, new SubProgressMonitor(monitor, 1));