class ActiveModel::Serializer

def self.get_serializer_for(klass, namespace = nil)
  return nil unless config.serializer_lookup_enabled
  cache_key = ActiveSupport::Cache.expand_cache_key(klass, namespace)
  serializers_cache.fetch_or_store(cache_key) do
    # NOTE(beauby): When we drop 1.9.3 support we can lazify the map for perfs.
    lookup_chain = serializer_lookup_chain_for(klass, namespace)
    serializer_class = lookup_chain.map(&:safe_constantize).find { |x| x && x < ActiveModel::Serializer }
    if serializer_class
      serializer_class
    elsif klass.superclass
      get_serializer_for(klass.superclass, namespace)
    else
      nil # No serializer found
    end
  end
end