Type of PageItem element

On my document I have for example 20 page itens, some of them could be ovals, textframes, graphic and so on. How can I check the type of page item?

For example:

for (int i=0; i< document.countPageItems();i++) {

     PageItem item = document.getAllChildPageItems()[i];

     TextFrame frame = TextFrameHelper.narrow(item); //Here, how can i know the exact type of my item?

}