MapNestedAttribute having keys that are known only at runtime

Terraform Providers
1

Hello,

In other programming languages the Map is a collection with key, value pairs that are only known at runtime. I want to do the same here, to be able to created 2 resources:

resource "example_bag" "bag1" {
  name 	  = "res1"
  content = [
    book 	= "How to draw"
    pen 	= "Color red"
  }
}
resource "example_bag" "bag2" {
  name 	  = "res1"
  content = [
    drink 	= "Beer"
    food 	= "Burger"
  }
}

But I don’t know the fields inside the Map content. Looking at the documentation of MapNestedAttribute we need to list all the attributes inside the Map, which is not possible. How can I describe correctly in the resource schema for my use case?

Thanks,
Valentin