/// Fields used herein nust be indexed (doesn't matter if these fields are stored or not). ///
/// It is assumed that each such indexed field is untokenized, or at least has a single token in a document. /// For documents with multiple tokens of the same field, behavior is undefined (It is likely that current /// code would use the value of one of these tokens, but this is not guaranteed). ///
/// Document with no tokens in this field are assigned the Zero
value.
///
///
/// WARNING: The status of the search.function package is experimental. /// The APIs introduced here might change in the future and will not be /// supported anymore in such a case. /// ///