请问聚合图里shape('point_count','text')里的point_count哪来的，可选值有哪些，怎么设置自定义值？

请问聚合图里shape('point_count','text')里的point_count哪来的，可选值有哪些，怎么设置自定义值？我以为这里的point_count只是演示文字，真实是填入data里的数值字段名，如geojson里properties里value什么的，我写了就不生效，不懂这个地方官方文档也写的不清楚，求指教

Start with the shape('point_count','text') entry point and the GeoJSON properties example described in the issue. Clarify where point_count comes from, list the supported values, and explain how a custom data field can be configured; the documentation is done when these questions are answered with a working example.

Written by the indexing model from the issue text.