def whitelist_class!(klass)
raise "#{klass} not a Class" unless klass.is_a?(::Class)
klass_name = klass.name
raise "#{klass} cannot be anonymous" if klass_name.nil? || klass_name.empty?
predefined_tag = PREDEFINED_TAGS[klass]
if predefined_tag
OPTIONS[:whitelisted_tags] << predefined_tag
return
end
tag_class = klass < Exception ? "exception" : "object"
tag_prefix = case YAML_ENGINE
when "psych" then "!ruby/#{tag_class}"
when "syck" then "tag:ruby.yaml.org,2002:#{tag_class}"
else raise "unknown YAML_ENGINE #{YAML_ENGINE}"
end
OPTIONS[:whitelisted_tags] << "#{tag_prefix}:#{klass_name}"
end