ActiveSupport::Deprecation::DeprecatedObjectProxy

This DeprecatedObjectProxy transforms object to deprecated object.

@old_object = DeprecatedObjectProxy.new(Object.new, "Don't use this object anymore!")
@old_object = DeprecatedObjectProxy.new(Object.new, "Don't use this object anymore!", deprecator_instance)

When someone executes any method except inspect on proxy object this will trigger warn method on deprecator_instance.

Default deprecator is ActiveSupport::Deprecation