• bigdecimal
• date
• ipaddr
• pathname
• uri/generic
• msgpack/bigint
• active_support/hash_with_indifferent_access
• active_support/core_ext/string/output_safety
• active_support/time

• 模块 ActiveSupport
• 模块 ActiveSupport::MessagePack
• 模块 URI
• 类 ActiveSupport::Duration
• 类 ActiveSupport::MessagePack::UnserializableObjectError