Bug 23366 Modify parameters refactoring remebers last state [refactoring]
2.x - select a method with 2 arguments - activate modify parameters - change order and one name - click next to see preview - press cancel - activate refactoring again observe: the dialog shows the last entered settings.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/ExtractInterfaceAction.java
if (first instanceof IType)
				return shouldAcceptElement((IType)first);
			if (first instanceof ICompilationUnit)	
				return shouldAcceptElement(JavaElementUtil.getMainType((ICompilationUnit)first));
			return false;
		} catch (JavaModelException e) {
			
			if (JavaModelUtil.filterNotPresentException(e))
				JavaPlugin.log(e); 
			return false;	
		}
	}
		
	private boolean canRun(ITextSelection selection){
		IJavaElement[] elements= resolveElements();
		if (elements.length != 1)
			return false;
		return (elements[0] instanceof IType) && shouldAcceptElement((IType)elements[0]);
	}
	private boolean shouldAcceptElement(IType type) {
		if (type == null)
			return false;
		try{
			fRefactoring= new ExtractInterfaceRefactoring(type, JavaPreferencesSettings.getCodeGenerationSettings());
			return fRefactoring.checkPreactivation().isOK();
		} catch (JavaModelException e) {
			
			if (JavaModelUtil.filterNotPresentException(e))
				JavaPlugin.log(e); 
			return false;