processingMode
int processingMode
"Full" processing mode starts by setting all bits to false and only setting bits
for documents that contain the given field and are identified as none-duplicates.
"Fast" processing sets all bits to true then unsets all duplicate docs found for the
given field. This approach avoids the need to read TermDocs for terms that are seen
to have a document frequency of exactly "1" (i.e. no duplicates). While a potentially
faster approach , the downside is that bitsets produced will include bits set for
documents that do not actually contain the field given.