String prefix = params.get(TermsParams.TERMS_PREFIX_STR);
boolean raw = params.getBool(TermsParams.TERMS_RAW, false);
for (int j = 0; j < fields.length; j++) {
String field = StringHelper.intern(fields[j]);
FieldType ft = raw ? null : rb.req.getSchema().getFieldTypeNoEx(field);
if (ft==null) ft = new StrField();
// If no lower bound was specified, use the prefix
String lower = lowerStr==null ? prefix : (raw ? lowerStr : ft.toInternal(lowerStr));
if (lower == null) lower="";
String upper = upperStr==null ? null : (raw ? upperStr : ft.toInternal(upperStr));