title: SOLR count of groups
body: <p><code>http://localhost:8080/solr/select?q=(apposta apposta per) OR (sue prime ore al)&amp;group=true&amp;group.field=grouping_field&amp;group.limit=5</code></p>
  
  <p>This query returns 2 groups first group has 1 document and second group has 2 documents.</p>
  
  <p>In response I see count of documents(3) but there is no counts of groups.
  How can I get count of groups.</p>