Warning in JaSerializer.PhoenixView not Understood

I have a custom render function in a view to send a complex json like this:

def render("slow.json-api", %{data: %{category: category, things: things, other_things: other_things}}) do
    data: %{
      category: render_one(category, ApiWeb.CategoryView , "show.json-api"),
      things: render_many(things, ApiWeb.ThingsView , "show.json-api"),
      other_things: render_many(other_things, ApiWeb.OtherThingsView , "show.json-api")

I get this warning:

warning:  Passing data via `:model`, `:categorys` or `:category`
          atoms to JaSerializer.PhoenixView has be deprecated. Please use
          `:data` instead. This will stop working in a future version.

Can anyone explain this behavior and tell me what I shall do?

That error comes from here:

It’s caused by render_one inflecting the parameter name on this line:

category: render_one(category, ApiWeb.CategoryView , "show.json-api"),

This ends up calling CategoryView’s render function with a category assign. Passing as: :data will prevent that behavior.