gistfile1.txt

namespace = options.fetch(:namespace, Object).name # V1 -> "V1
resource_namespace = resource.class.name.deconstantize  #  "Doorkeeper::AcccessToken" -> "Doorkeeper"
_module = "#{namespace}::#{resource_namespace}".constantize # V1::Doorkeeper
_module.const_get "#{resource.class.name.demodulize}Serializer" # const_get "AccessTokenSerializer"