def identifier
      @identifier ||= begin
        uri = @representor_hash.href || self.object_id
        protocol = @representor_hash.protocol || (uri == self.object_id ? UNKNOWN_PROTOCOL : DEFAULT_PROTOCOL)
        PROTOCOL_TEMPLATE % [protocol, uri]
      end
    end
def identifier
      @identifier ||= begin
        uri = @representor_hash.href || self.object_id
        protocol = @representor_hash.protocol || (uri == self.object_id ? UNKNOWN_PROTOCOL : DEFAULT_PROTOCOL)
        PROTOCOL_TEMPLATE % [protocol, uri]
      end
    end
The URI for the object

 @note If the URI can't be made from the provided information it constructs one from the Ruby ID
 @return [String]