SolrQuery::setGroupLimit — Specifies the number of results to return for each group. The server default value is 1
SolrQuery::setGroupMain — If true, the result of the first field grouping command is used as the main result list in the response, using group.format=simple
SolrQuery::setGroupNGroups — If true, Solr includes the number of groups that have matched the query in the results
SolrDisMaxQuery::setQueryPhraseSlop — Specifies the amount of slop permitted on phrase queries explicitly included in the user's query string (qf parameter)