class RuboCop::Cop::Style::ObjectThen

def check_method_node(node)
  return unless preferred_method?(node)
  message = message(node)
  add_offense(node.loc.selector, message: message) do |corrector|
    prefer = style == :then && node.receiver.nil? ? 'self.then' : style
    corrector.replace(node.loc.selector, prefer)
  end
end