def ignore_by_class?(ignored_class = nil)
      @ignore_by_class ||= Proc.new do |ignored_class|
        case error_class
        when (ignored_class.respond_to?(:name) ? ignored_class.name : ignored_class)
          true
        else
          exception && ignored_class.is_a?(Class) && exception.class < ignored_class
        end
      end

      ignored_class ? @ignore_by_class.call(ignored_class) : config.ignored_classes.any?(&@ignore_by_class)
    end
def ignore_by_class?(ignored_class = nil)
      @ignore_by_class ||= Proc.new do |ignored_class|
        case error_class
        when (ignored_class.respond_to?(:name) ? ignored_class.name : ignored_class)
          true
        else
          exception && ignored_class.is_a?(Class) && exception.class < ignored_class
        end
      end

      ignored_class ? @ignore_by_class.call(ignored_class) : config.ignored_classes.any?(&@ignore_by_class)
    end
Determines if error class should be ignored.

 ignored_class_name - The name of the ignored class. May be a
 string or regexp (optional).

 Returns true or false.