How to do Projection in "GraphQL.Net"?

Question

I have problem with using GraphQL.Net, and that is what I need. I specify four fields in aType Class, when I try to fetch only two fields with a query on GraphQL, the executing query on database contains all four fields that defined in Type class but I expect query to be something look like this :
Select field1,field2 from someEntity

How to do this projection ?!
I'm using GraphQL.Net version 7.2.2