How can I specify a column of java object in my sql select list after switching to calcite

[tore yang via user]

My cache has a column of type java map, the column name is "mymap". when I send 
a query "select id,mymap from mytable", it complains "Error: Failed to parse 
the query. (state=4200,code=1001). but when I run the query "select * from 
mytable", the column mymap returns perfectly. this wasn't a problem until I 
replaced "H2" with "Calcite", and it only fails for column with data type 
java.lang.objects. 
How to specify the column which is of type "java object".
Thanks!