Allow specifying an execution hint for terms facets.
- method:uif, for an indexed multi-valued field without docvalues, use top-level UnInvertedField method of faceting, which generally gives better performance for non-NRT use cases
- method:dv, for an indexed multi-valued field without docvalues, use heap DocValues created on-the-fly, which generally gives better performance for NRT use cases
- method:stream, to calculate buckets on the fly while returning the response. Does not support all options.
- method:enum - not implemented yet
- method:smart - solr should choose best (default, but not really implemented yet)