def flusher
      name = @name
      [:before_validation,:after_validation].each do |operation|
        @klass.send(operation) do

          %w(size extension identifier).each do |attribute|
            if errors.include?(:"#{name}_#{attribute}")
              errors[:"#{name}_#{attribute}"].each do |message|
                errors.add(name, message)
              end
              errors[:"#{name}_#{attribute}"].clear
            end
          end
        end
      end
    end
def flusher
      name = @name
      [:before_validation,:after_validation].each do |operation|
        @klass.send(operation) do

          %w(size extension identifier).each do |attribute|
            if errors.include?(:"#{name}_#{attribute}")
              errors[:"#{name}_#{attribute}"].each do |message|
                errors.add(name, message)
              end
              errors[:"#{name}_#{attribute}"].clear
            end
          end
        end
      end
    end
Flush validations.

 Usage:

   attacher.flusher