following: https://github.com/rails-api/active_model_serializers/issues/1268#issuecomment-148144139 - [x] rename `options[:context]` in the controller etc. to `options[:serialization_context]` #1289 - [x] test an example of passing in a custom `serialization_context` #1289 - [x] create a `SerializationContext` object that wraps the `request` and exposes `original_url` and `query_parameters` #1289 - [x] consider using the SerializationContext to expose the request `media_type` and `api_version` and `url_helpers` - [x] ref api version: https://github.com/rails-api/active_model_serializers/pull/1265#issuecomment-147267020 - [x] ref media type: https://github.com/rails-api/active_model_serializers/pull/1082 - [x] ref url helpers: https://github.com/rails-api/active_model_serializers/pull/1282 https://github.com/rails-api/active_model_serializers/pull/666 https://github.com/rails-api/active_model_serializers/pull/1289#discussion_r42808317