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)