class Honeybadger::Rack::UserInformer

when an error has occurred.
Middleware for Rack applications. Adds an error ID to the Rack response

def agent 

def agent
  @agent || Honeybadger::Agent.instance
end

def call(env) 

def call(env)
  status, headers, body = @app.call(env)
  if env["honeybadger.error_id"]
    new_body = []
    replace = replacement(env["honeybadger.error_id"])
    body.each do |chunk|
      new_body << chunk.gsub("<!-- HONEYBADGER ERROR -->", replace)
    end
    body.close if body.respond_to?(:close)
    headers["Content-Length"] = new_body.reduce(0) { |a, e| a + e.bytesize }.to_s
    body = new_body
  end
  [status, headers, body]
end

def initialize(app, agent = nil) 

def initialize(app, agent = nil)
  @app = app
  @agent = agent.is_a?(Agent) && agent
end

def replacement(with) 

def replacement(with)
  config[:"user_informer.info"].gsub(/\{\{\s*error_id\s*\}\}/, with.to_s)
end