code: protected void processHighlightOptions(SolrQuery solrQuery, HighlightQuery query, @Nullable Class<?> domainType) {
  
  		if (query.hasHighlightOptions()) {
  
  			HighlightOptions highlightOptions = query.getHighlightOptions();
  			solrQuery.setHighlight(true);
  
  			if (!highlightOptions.hasFields()) {
  				solrQuery.addHighlightField(HighlightOptions.ALL_FIELDS.getName());
  			} else {
  				for (Field field : highlightOptions.getFields()) {
  					solrQuery.addHighlightField(getMappedFieldName(field, domainType));
  				}
  				for (FieldWithHighlightParameters fieldWithHighlightParameters : highlightOptions
  						.getFieldsWithHighlightParameters()) {
  					addPerFieldHighlightParameters(solrQuery, fieldWithHighlightParameters, domainType);
  				}
  			}
  
  			for (HighlightParameter option : highlightOptions.getHighlightParameters()) {
  				addOptionToSolrQuery(solrQuery, option);
  			}
  
  			if (highlightOptions.hasQuery()) {
  				solrQuery.add(HighlightParams.Q, getQueryString(highlightOptions.getQuery(), domainType));
  			}
  		}
  	}
docs: Append highlighting parameters to {@link SolrQuery}
  
  @param solrQuery the target {@link SolrQuery}
  @param query the source query.
  @param domainType used for mapping fields to properties. Can be {@literal null}.