# File lib/cgikit.rb, line 1531
                def check_required_attributes( *patterns )
                        requires = 0
                        attrs    = []
                        pattern  = attr = nil

                        patterns.each do | pattern |
                                pattern.each do | attr |
                                        requires += 1 if definition.include? attr
                                end

                                return true if requires == pattern.size
                                requires = 0
                                attrs << ( "'" + pattern.join(', ') + "'" )
                        end

                        message =  "#{self.class} requires #{attrs.join(' or ')} "
                        message << "of attribute - #{name_with_class}"
                        raise AttributeError, message
                end