Data::Object::Role::Arguable provides a mechanism for unpacking an argument list
and creating a data structure suitable for passing to the consumer constructor.
The argslist routine should return a list of attribute names in the order to be
parsed. An attribute name maybe prefixed with "@" to denote that all remaining
items should be assigned to an arrayref, e.g. @options, or "%" to denote that
all remaining items should be assigned to a hashref, e.g. %options.
