(PECL solr >= 2.7.0)
SolrQuery::setHighlightQuery — A query designated for highlighting (hl.q)
A query to use for highlighting. This parameter allows one to highlight different terms or fields than those being used to retrieve documents.
Default value when not set: the value of the request's q parameter
Solr Parameter reference: hl.q
qHighlight Query
Returns the current SolrQuery object, if the return value is used.