How to implement multiple different serializers for same model using ActiveModel::Serializers?

You can have multiple serializers for the same model, e.g.

class SimplePersonSerializer < ActiveModel::Serializer
  attributes :id, :name
end

and

class CompletePersonSerializer < ActiveModel::Serializer
  attributes :id, :name, :phone, :email
end

simple info for people in one controller:

render json: @people, each_serializer: SimplePersonSerializer

complete info for people in another:

render json: @people, each_serializer: CompletePersonSerializer

simple info for a single person:

render json: @person, serializer: SimplePersonSerializer

complete info for a single person:

render json: @person, serializer: CompletePersonSerializer