code: @SuppressWarnings("ConstantConditions")
      public void _whereLucene(String fieldName, String whereClause, boolean exact) {
          fieldName = ensureValidFieldName(fieldName, false);
  
          List<QueryToken> tokens = getCurrentWhereTokens();
          appendOperatorIfNeeded(tokens);
          negateIfNeeded(tokens, fieldName);
  
          WhereToken.WhereOptions options = exact ? new WhereToken.WhereOptions(exact) : null;
          WhereToken whereToken = WhereToken.create(WhereOperator.LUCENE, fieldName, addQueryParameter(whereClause), options);
          tokens.add(whereToken);
      }
docs: Filter the results from the index using the specified where clause.
  @param fieldName Field name
  @param whereClause Where clause
  @param exact Use exact matcher