result.merge(collectAndCheckImports());
	public RefactoringStatus checkInput(IProgressMonitor pm) throws JavaModelException {		try{			pm.beginTask(RefactoringCoreMessages.getString("ChangeSignatureRefactoring.checking_preconditions"), 5); //$NON-NLS-1$			RefactoringStatus result= new RefactoringStatus();			if (isSignatureSameAsInitial())				return RefactoringStatus.createFatalErrorStatus(RefactoringCoreMessages.getString("ChangeSignatureRefactoring.unchanged")); //$NON-NLS-1$			result.merge(checkSignature());			if (result.hasFatalError())				return result;			fRippleMethods= RippleMethodFinder.getRelatedMethods(fMethod, new SubProgressMonitor(pm, 1), null);			fOccurrenceNodes= findOccurrenceNodes(new SubProgressMonitor(pm, 1));						result.merge(checkVisibilityChanges());								if (! isOrderSameAsInitial())					result.merge(checkReorderings(new SubProgressMonitor(pm, 1)));				else pm.worked(1);						if (result.hasFatalError())				return result;			fChangeManager= createChangeManager(new SubProgressMonitor(pm, 1));			result.merge(checkIfDeletedParametersUsed());			if (mustAnalyzeAst()) 				result.merge(analyzeAst()); 			if (result.hasFatalError())				return result;			result.merge(validateModifiesFiles());			return result;		} catch (CoreException e){				throw new JavaModelException(e);		} finally{			pm.done();		}	}