The word to get

Buffer to receive the text

Size of the buffer pointed to by buf

[Output] Number of times the word occurs in the index
Note: To make WordListBuilder fast, it does not actually enumerate all of the references for each word, so in some cases the counts can include artifacts of the indexing process such as removed or reindexed documents, which can make the reported counts higher than the actual counts in the index. Compressing an index will eliminate these extra references.