Issues With NifMap in Rustler with Elixir

Hi!

I am currently having an issue with rustler, where I am trying to declare a struct as an NifMap to pass some data in from elixir.

However, I keep getting the following error.

error[E0599]: no method named `encode` found for struct `rustler::types::atom::Atom` in the current scope
  --> src/ta_router.rs:9:10
   |
9  | #[derive(rustler::NifMap)]
   |          ^^^^^^^^^^^^^^^ method not found in `rustler::types::atom::Atom`

Note that when I use NifStruct and bound it to a module, I do not get any compilation errors.

The reference documentation is located here

Any help would be much appreciated