if (!(resource instanceof IFile)) return false;
	public boolean performDrop(Object data) {		if (data == null) return false;        if(data instanceof IResource[]) {           IResource[] sources = (IResource[])data;           if (sources.length == 0) return false;           IResource resource = sources[0];           if (!(resource instanceof IFile)) return false;           view.showHistory(resource, true /* fetch */);           return true;        } else if( data instanceof ISVNRemoteResource) {            view.showHistory((ISVNRemoteResource) data, null); // true /* fetch */);            return true;        }        return false;        	}