如何在Lucene 4中获得Lucene字段的所有项

I'm trying to update my code from Lucene 3.4 to 4.1. I figured out the changes except one. I have code which needs to iterate over all term values for one field. In Lucene 3.1 there was an IndexReader#terms() method providing a TermEnum, which I could iterate over. This seems to have changed for Lucene 4.1 and even after several hours of search in the documentation I am not able to figure out how. Can someone please point me in the right direction?I'm trying to update my code from Lucene 3.4 to