# File lib/set.rb, line 272def proper_superset?(set)casewhenset.instance_of?(self.class)&&@hash.respond_to?(:>)@hash>set.instance_variable_get(:@hash)whenset.is_a?(Set)size>set.size&&set.all?{|o|include?(o)}elseraiseArgumentError,"value must be a set"endend