Required Files
- active_support/core_ext/array/extract_options
- active_support/core_ext/array/wrap
- active_support/core_ext/class/attribute
- active_support/core_ext/hash/keys
- active_support/core_ext/hash/except
- active_model/errors
- active_model/validations/callbacks
Namespace
- MODULE ActiveModel
- MODULE ActiveModel::Validations
- MODULE ActiveModel::Validations::ClassMethods