class Capybara::Selector

def call(locator, **options)
  if format
    raise ArgumentError, "Selector #{@name} does not support #{format}" unless expressions.key?(format)
    instance_exec(locator, **options, &expressions[format])
  else
    warn 'Selector has no format'
  end
ensure
  unless locator_valid?(locator)
    Capybara::Helpers.warn(
      "Locator #{locator.class}:#{locator.inspect} for selector #{name.inspect} must #{locator_description}. " \
      'This will raise an error in a future version of Capybara. ' \
      "Called from: #{Capybara::Helpers.filter_backtrace(caller)}"
    )
  end
end