class Selenium::WebDriver::Support::Select

def deselect_by_value(value)
  raise Error::UnsupportedOperationError, 'you may only deselect option of a multi-select' unless multiple?
  opts = find_by_value value
  return deselect_options(opts) unless opts.empty?
  raise Error::NoSuchElementError, "cannot locate option with value: #{value.inspect}"
end