code: @Override
      public MarkLogicBooleanQuery prepareBooleanQuery(String queryString) throws RepositoryException, MalformedQueryException {
          return prepareBooleanQuery(QueryLanguage.SPARQL, queryString, null);
      }
docs: overload for prepareBooleanQuery
  
  @param queryString
  @return MarkLogicBooleanQuery
  @throws RepositoryException
  @throws MalformedQueryException