docstore/memdocstore: execution order of OrderBy and Limit

In memdocstore, OrderBy is executed after Limit. Is this intended befavior?

For example, there is a data set which is 'a' to 'z' as field 'id'. (Created from 'a' to 'z'.)
If execute query below, it returns 'x', 'y', 'z'. But it should be 'a', 'b', 'c'.
coll.Where("id", ">", "").OrderBy("id", docstore.Ascending).Limit(3)
