# File lib/declarative_authorization/authorization.rb, line 365
    def validate? (attr_validator, skip_attribute = false)
      skip_attribute or @attributes.empty? or
        @attributes.send(@join_operator == :and ? :all? : :any?) do |attr|
          begin
            attr.validate?(attr_validator)
          rescue NilAttributeValueError => e
            nil # Bumping up against a nil attribute value flunks the rule.
          end
        end
    end