You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: webfinger.rb
    path of file: ./repos/mastodon/app/lib
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class Webfinger
  class Err
    
  def perform
    Response.new(@uri, body_from_webfinger)
  rescue Oj::ParseError
    raise Webfinger::Error, "Invalid JSON in response for #{@uri}"
  rescue Addressable::URI::InvalidURIError
    raise Webfinger::Error, "Invalid URI for #{@uri}"
  end