Query fields currently require that a single return type. While it enforces a strongly typed repository, and benefits GraphQL, it may not always be what people want.

Add an option "any" to the list.

Note: a more creative alternative would be to add "virtual" types to the list, that can be defined within the query field package. They would define a set of common arguments, potentially mapped to fields from different types; a kind of pre-version of abstract types.