}
private FieldCollapseResponse.CollapseGroup getCollapseGroup(String field) {
FieldCollapseResponse cResp = this.queryResults.getFieldCollapseResponse();
/** make lookup map */
for (FieldCollapseResponse.CollapseGroup grp : cResp.getCollapseGroups()) {
String handlePrefix = ConfigurationManager.getProperty("handle.canonical.prefix");
if (handlePrefix == null || handlePrefix.length() == 0)
{
handlePrefix = "http://hdl.handle.net/";