docs: public synchronized CallableStatement prepareCall(String sql,
              int resultSetType, int resultSetConcurrency,
              int resultSetHoldability) throws SQLException {
  
          checkClosed();
  
          try {
              return new JDBCCallableStatement(this, sql, resultSetType,
                      resultSetConcurrency, resultSetHoldability);
          } catch (HsqlException e) {
              throw Util.sqlException(e);
          }
      }