+require 'common/errors'
+
+class Domain
+
+ @domain = nil
+
+ def initialize(domain)
+ if domain.empty? then
+ msg = "domain cannot be empty"
+ raise InvalidDomainError.new(msg)
+ end
+
+ @domain = domain
+ end
+
+ def to_s()
+ return @domain
+ end
+
+ def ==(other)
+ return self.to_s() == other.to_s()
+ end
+end