class ActiveModel::Validations::ConfirmationValidator

def validate_each(record, attribute, value)
  unless (confirmed = record.public_send("#{attribute}_confirmation")).nil?
    unless confirmation_value_equal?(record, attribute, value, confirmed)
      human_attribute_name = record.class.human_attribute_name(attribute)
      record.errors.add(:"#{attribute}_confirmation", :confirmation, **options.except(:case_sensitive).merge!(attribute: human_attribute_name))
    end
  end
end