code: public <U> U forStream(
              String fileName,
              Function<? super Stream<Map<String, Object>>, U> handleStream) {
          String sql = getTemplate(fileName, EMPTY_ARGS);
          PreparedStatementSetter pss = paramBuilder.byArgs(new Object[0]);
          RowMapper<Map<String, Object>> mapper = new ColumnMapRowMapper();
          return queryStreamWithOrdinalParams(sql, pss, mapper, handleStream);
      }
docs: Executes a query,
  passing the column maps to {@code handleStream} as a stream.
  
  <p>Example usage:</p>
  
  <pre>
  int totalSalary = sqlTemplate.forStream("/path/to/query.sql",
  mapStream -&gt; mapStream.mapToInt(map -&gt; (Integer) map.get("salary")).sum());
  </pre>
  
  @param fileName SQL specifier
  @param handleStream the function which is applied to the stream
  @param <U> the result type
  @return the result of {@code handleStream}
  @throws org.springframework.dao.DataAccessException if there is any problem